uk mod requirements for domestic hot and cold fresh water systems - 00000300

Ministry of Defence Defence Standard 02-728 Issue 3 Publication Date 03 September 2010

Requirements for Domestic Hot and Cold Fresh Water Systems

Category 3

Def Stan 02-728 Issue 3

Contents

Foreword ........................................................................................................................................................viii 1 Scope.......................................................................................................................................................1 2 Warning ...................................................................................................................................................1 3 Normative References ...........................................................................................................................1 4 Definitions ...............................................................................................................................................1 5 Abbreviations..........................................................................................................................................1 6 Performance Specification ....................................................................................................................2 6.1 Drawings ............................................................................................................................................2 6.1.1 System Diagrammatic Arrangement Drawings.........................................................................2 6.1.2 System Ship Arrangement Drawings.........................................................................................3 6.1.3 Equipment Drawings ...................................................................................................................3 6.2 Materials.............................................................................................................................................4 6.2.1 Material Selection.........................................................................................................................4 6.2.2 Fresh Water Storage Tanks.........................................................................................................4 6.2.3 Accumulators ...............................................................................................................................5 6.2.4 Pumps ...........................................................................................................................................5 6.2.5 Calorifiers......................................................................................................................................5 6.2.6 Valves ............................................................................................................................................5 6.2.7 Strainers........................................................................................................................................5 6.2.8 Pipework .......................................................................................................................................5 6.2.9 Steel Pipework..............................................................................................................................5 6.2.10 Screwed Fasteners ......................................................................................................................5 6.2.11 Jointing .........................................................................................................................................5 6.2.12 Insulation ......................................................................................................................................6 6.3 System General Requirements ........................................................................................................6 6.3.1 General ..........................................................................................................................................6 6.3.2 Hot Water System, Services Supplies .......................................................................................6 6.3.2.1 HM Surface Ships....................................................................................................................6 6.3.2.2 Submarines..............................................................................................................................7 6.3.3 Battery Top–up Water (Submarines)..........................................................................................7 6.4 System Arrangement ........................................................................................................................7 6.4.1 Cold Fresh Water in HM Surface Ships .....................................................................................7 6.4.2 Cold Fresh Water in Submarines ...............................................................................................9 6.4.3 Provision of Washbasins and Showers.....................................................................................9

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6.4.4 System Requirements .................................................................................................................9 6.4.4.1 Submarines............................................................................................................................13 6.4.5 Hot Fresh Water Systems .........................................................................................................14 6.4.5.1 HM Surface Ships .................................................................................................................14 6.4.5.2 Submarines............................................................................................................................16 6.4.6 Emergency Fresh Water Supply to Sonar Cooling System...................................................17 6.5 Desalination Requirements............................................................................................................17 6.5.1 General........................................................................................................................................17 6.5.2 Submarines.................................................................................................................................17 6.6 Fresh Water Storage and Filling ....................................................................................................17 6.6.1 Storage Capacity........................................................................................................................17 6.6.2 Storage Tank Arrangement.......................................................................................................18 6.6.2.1 HM Surface Ships .................................................................................................................18 6.6.2.2 Submarines............................................................................................................................18 6.6.3 Filling Arrangements .................................................................................................................18 6.6.3.1 HM Surface Ships .................................................................................................................18 6.6.3.2 Submarines............................................................................................................................20 6.6.4 Filtering .......................................................................................................................................20 6.6.5 Sterilization.................................................................................................................................20 6.6.6 Sounding Tubes .........................................................................................................................21 6.6.7 Air Escapes.................................................................................................................................21 6.7 Pump Selection ...............................................................................................................................22 6.7.1 General........................................................................................................................................22 6.7.2 Cold Water Pump .......................................................................................................................22 6.7.3 Cold Water Boost Pump............................................................................................................22 6.7.4 Hot Water Pump .........................................................................................................................22 6.7.5 Hot Water Boost Pump..............................................................................................................22 6.7.6 Pump Protection ........................................................................................................................23 6.8 Calorifiers.........................................................................................................................................23 6.8.1 Types of Equipment...................................................................................................................23 6.8.2 Heating Capacity ........................................................................................................................23 6.8.3 General Requirements...............................................................................................................23 6.8.4 Submarines.................................................................................................................................24 6.9 Drinking Water and Cooled Fresh Water ......................................................................................24 6.9.1 Emergency Drinking Water .......................................................................................................24 6.9.2 Drinking Water Coolers and Ice Making Machines.................................................................25 6.9.3 Cooled Fresh Water ...................................................................................................................25 6.10 Auxiliary Components ....................................................................................................................25 6.10.1 Accumulators .............................................................................................................................25

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Def Stan 02-728 Issue 3 6.10.2 Submarine Tank Air Pressure Charging Equipment ..............................................................26 6.10.3 Pipework .....................................................................................................................................26 6.10.3.1 Steel Piping............................................................................................................................26 6.10.3.2 Non-Ferrous Piping...............................................................................................................26 6.10.4 Air Release Units........................................................................................................................27 6.11 System Details.................................................................................................................................28 6.11.1 Introduction ................................................................................................................................28 6.11.2 Hot and Cold Water Systems....................................................................................................28 6.11.3 Review of General Design.........................................................................................................33 6.11.4 Supplies to Washbasins and Showers ....................................................................................33 6.11.5 Diversity Factors for Outlets.....................................................................................................33 6.11.6 Cold Water Pump .......................................................................................................................34 6.11.7 Cold Water Boost Pump............................................................................................................35 6.11.8 Pressure at Outlets ....................................................................................................................36 6.11.9 Hot Water Circulation ................................................................................................................37 6.11.10 Selection of Calorifier ................................................................................................................38 6.11.11 Hot Water System Peak Load ...................................................................................................39 6.11.12 Hot Water Storage Capacity......................................................................................................39 6.11.13 Electric Water Heaters ...............................................................................................................46 6.11.14 Accumulator for Thermal Expansion .......................................................................................46 6.11.15 Provision for Air Removal .........................................................................................................46 6.12 Installation and Testing ..................................................................................................................48 6.12.1 General ........................................................................................................................................48 6.12.2 Fresh Water Storage Tanks.......................................................................................................48 6.12.3 Piping Installation ......................................................................................................................48 6.12.4 Welding .......................................................................................................................................50 6.12.5 Brazing ........................................................................................................................................50 6.12.6 Pipe Manipulation ......................................................................................................................50 6.12.7 Castings ......................................................................................................................................51 6.12.8 Cleaning and Preservation........................................................................................................51 6.12.8.1 General...................................................................................................................................51 6.12.8.2 Fresh Water Storage Tanks .................................................................................................51 6.12.8.3 Tubes and Pipes....................................................................................................................51 6.12.9 Fresh Water Tank Calibration ...................................................................................................51 6.12.10 Pressure Tests ...........................................................................................................................51 6.12.10.1 Tanks......................................................................................................................................51 6.12.10.2 Valves.....................................................................................................................................52 6.12.10.3 Pipework in Submarines ......................................................................................................52 6.12.11 Trials............................................................................................................................................52

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6.12.12 Inspection and Flushing............................................................................................................53 6.12.13 Insulation ....................................................................................................................................53 6.12.14 Colours and Marking .................................................................................................................53 Annex A Normative References....................................................................................................................54 A.1 Reference Information ....................................................................................................................54 Annex B Definitions .......................................................................................................................................58 B.1 Definitions........................................................................................................................................58 Annex C Sample Calculations and Formula ................................................................................................60 C.1 Introduction .....................................................................................................................................60 C.2 General Calculations ......................................................................................................................60 C.3 Water Flow and Approximate Pipe Bore Calculation (Cold Water System)..............................63 C.4 Physical Data (Cold Water System)...............................................................................................66 C.5 Pipe Friction Calculations (Cold Water System Main) ................................................................68 C.6 Pipe Friction Calculations (Cold Water System Branches) ........................................................71 C.7 Selection of Cold Water Pump and Cold Water Boost Pump.....................................................73 C.8 Water Flow Rates From Calorifiers ...............................................................................................75 C.9 Water Flow and Approximate Pipe Bore Calculation (Hot Water System)................................77 C.10 Water Flow and Approximate Pipe Bore Calculation ..................................................................78 C.11 Physical Data (Hot Water System).................................................................................................78 C.12 Physical Data For Hot Water Branches (Aft) ................................................................................79 C.13 Pipe Friction Calculations (Hot Water System Main) ..................................................................79 C.14 Pipe Friction Calculations (Hot Water System Branches) ..........................................................81 C.15 Pressures Required and Available at Calorifier(s) ......................................................................82 C.16 Duty of Hot Water Circulating Pump.............................................................................................83 C.17 Capacity of Accumulators..............................................................................................................85 Annex D Types of Backflow Preventor ........................................................................................................87

Figures

Figure 1 - Typical Domestic Cold Water System for HM Surface Ships ...................................................11 Figure 2 - Typical Domestic Cold Water System for Submarines .............................................................13 Figure 3 - Typical Domestic Hot Water System for HM Surface Ships .....................................................15 Figure 4 - Typical Domestic Hot Water System for Submarines ...............................................................16 Figure 5 - Typical Automatic Air Release Valve ..........................................................................................27 Figure 6 - Piping System Pressure Loss Chart (Fresh Water 10°C)..........................................................31 Figure 7 - Piping System Pressure Loss Chart (Fresh Water 75°C).........................................................32 Figure 8 - Diversity Factor: Number of Fittings Connected .......................................................................35 Figure 9 - Washbasin Taps and Shower Head Fittings - Fitting of Orifice Plates....................................37 Figure 10 - Hot Water Temperature from Calorifier: Time for a Storage Capacity of 0.023m3 ...............41

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Def Stan 02-728 Issue 3 Figure 11 - Hot Water Temperature from Calorifier: Time for a Storage Capacity of 0.27m3..................42 Figure 12 - Hot Water Temperature from Calorifier: Time for a Storage Capacity of 0.455m3 ...............43 Figure 13 - Hot Water Temperature from Calorifier: Time for a Storage Capacity of 0.91m3..................44 Figure 14 - Hot Water Temperature: Time Effect of Change in Storage Capacity ...................................45 Figure 15 - Typical Air Collecting Vessel .....................................................................................................47 Figure 16 - Air Collecting Vessel and Manual Air Release.........................................................................47 Figure 17 - Air Collecting Vessel and Automatic Air Release....................................................................48

Tables

Table 1 - Scale of Electric Water Heaters.....................................................................................................24 Table 2 - Range of Alternative Calorifiers ....................................................................................................24 Table 3 - Range of Accumulators..................................................................................................................26 Table 4 - Domestic Fresh Water Systems, Pipe Size and Water Speeds..................................................28 Table 5 - Equivalent Straight Pipe Length for Valves, Bends, Tees, etc...................................................30 Table 6 - Example of Pump Fits ....................................................................................................................33 Table 7 - Discharge Rate for Fittings ............................................................................................................34 Table 8 - Range of Orifice Plates...................................................................................................................37 Table 9 - Conditions for Thermo–Siphon.....................................................................................................38 Table 10 - Hot Water Piping Heat Emission and Temperature Drop .........................................................38 Table 11 - Welding Requirements .................................................................................................................50 Table C.1 - Calculation Data Sheet C1/1 General Circulation ....................................................................62 Table C.2 - Calculation Data Sheet C2/1 Water Flow and Approximate Pipe Bore Calculation .............63 Table C.3 - Calculation Data Sheet C2/2 Water Flow and Approximate Pipe Bore Calculation .............64 Table C.4 - Calculation Data Sheet C2/3 Water Flow and Approximate Pipe Bore Calculation .............65 Table C.5 - Calculation Data Sheet C3/1 Physical Data ..............................................................................66 Table C.6 - Calculation Data Sheet C3/2 Physical Data ..............................................................................67 Table C.7 - Calculation Data Sheet C3/3 Physical Data ..............................................................................67 Table C.8 - Calculation Data Sheet C4/1 Pipe Friction Calculations .........................................................69 Table C.9 - Calculation Data Sheet C4/2 Pipe Friction Calculations .........................................................70 Table C.10 - Calculation Data Sheet C4/3 Pipe Friction Calculations .......................................................72 Table C.11 - Calculation Data Sheets C5 Selection of Cold Water Pump and Cold Water Boost

Pump ..............................................................................................................................................74 Table C.12 - Calculation Data Sheet C6 Hot Water Flow from Calorifiers ................................................76 Table C.13 - Calculation Data Sheet C7/1 Water Flow and Approximate Pipe Bore Calculation ...........77 Table C.14 - Calculation Data Sheet C7/2 Water Flow and Approximate Pipe Bore Calculation ...........78 Table C.15 - Calculation Data Sheet C8/1 Physical Data ............................................................................78 Table C.16 - Calculation Data Sheet C8/2 Physical Data ............................................................................79 Table C.17 - Calculation Data Sheet C9/1 Pipe Friction Calculations .......................................................80

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Table C.18 - Calculation Data Sheet C9/2 Pipe Friction Calculations .......................................................81 Table C.19 - Calculation Data Sheet C10 Pressures Required and Available at Calorifier(S) ................83 Table C.20 - Calculation Data Sheet C11 Duty of Hot Water Circulating Pump .......................................85 Table C.21 - Calculation Data Sheet C12 Capacity of Accumulators........................................................86

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Foreword

AMENDMENT RECORD

Amd No Date Text Affected Signature and Date

REVISION NOTE

This standard is raised to Issue 3 to update its content.

HISTORICAL RECORD

This standard supersedes the following:

Def Stan 02-728 Issue 2 6 Apr 2001

Def Stan 02-728 Issue 1 1 Apr 2000

NES 728 Issue 2 1994

NES 728 Issue 1 Oct 1982

SDP 26 1 June 1977

Sponsorship

1. This Defence Standard (Def Stan) is sponsored by the Defence Equipment and Support, Fleet Wide Systems, Maritime Equipment Systems, Output Business Unit (DES FWE-MES OBU), Ministry of Defence (MOD).

2. The complete Def Stan 02-728 Issue 3 comprises:


3. If it is found to be unsuitable for any particular requirement the MOD is to be informed in writing of the circumstances.

4. Any user of this Defence Standard either within MOD or in industry may propose an amendment to it. Proposals for amendments that are not directly applicable to a particular contract are to be made to the publishing authority identified on Rear Cover, and those directly applicable to a particular contract are to be dealt with using contract procedures.

5. No alteration is to be made to this Defence Standard except by the issue of an authorised amendment.

6. Unless otherwise stated, reference in this Defence Standard to approval, approved, authorised or similar terms, means the Ministry of Defence in writing.

7. Any significant amendments that may be made to this Defence Standard at a later date will be indicated by a vertical sideline. Deletions will be indicated by 000 appearing at the end of the line interval.

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8. Extracts from British Standards within this Defence Standard have been included with the permission of the British Standards Institution.

Conditions of Release

General

9. This Defence Standard has been devised solely for the use of the MOD, and its contractors in the execution of contracts for the MOD. To the extent permitted by law, the Crown hereby excludes all liability whatsoever and howsoever arising (including but without limitation, liability resulting from negligence) for any loss or damage however caused when the Defence Standard is used for any other purpose.

10. This document is Crown Copyright and the information herein may be subject to Crown or third party rights. It is not to be released, reproduced or published without written permission of the MOD.

11. The Crown reserves the right to amend or modify the contents of this Defence Standard without consulting or informing any holder.

MOD Tender or Contract Process

12. This Defence Standard is the property of the Crown. Unless otherwise authorised in writing by the MOD must be returned on completion of the contract or submission of the tender in connection with which it is issued.

13. When this Defence Standard is used in connection with a MOD tender or contract, the user is to ensure that he is in possession of the appropriate version of each document, including related documents, relevant to each particular tender or contract. Enquiries in this connection may be made of the Authority named in the tender or contract.

14. When Defence Standards are incorporated into contracts, users are responsible for their correct application and for complying with contractual and other statutory requirements. Compliance with a Defence Standard does not of itself confer immunity from legal obligations.

Categories of Naval Defence Standard

15. The Category of this Naval Defence Standard has been determined using the following criteria:

a) Category 1. If not applied may have a Critical affect on the following: Safety of the vessel, its complement or third parties. Operational performance of the vessel, its systems or equipment.

b) Category 2. If not applied may have a Significant affect on the following: Safety of the vessel, its complement or third parties. Operational performance of the vessel, its systems or equipment. Through life costs and support.

c) Category 3. If not applied may have a Minor affect on the following: MOD best practice and fleet commonality. Corporate experience and knowledge. Current support practice.

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Def Stan 02-728 Issue 3 Related Documents

16. In the tender and procurement processes the related documents in Annex A can be obtained as follows:

a) British Standards British Standards Institution, 389 Chiswick High Road, London, W4 4AL

b) Defence Standards Defence Equipment and Support UK Defence Standardization, Kentigern House 65 Brown Street, Glasgow, G2 8EX

c) Other documents Tender or Contract Sponsor to advise.

17. All applications to Ministry Establishments for related documents are to quote the relevant MOD Invitation to Tender or Contract Number and date, together with the sponsoring Directorate and the Tender or Contract Sponsor.

18. Prime Contractors are responsible for supplying their subcontractors with relevant documentation, including specifications, standards and drawings.

Health and Safety

Warning

19. This Defence Standard may call for the use of processes, substances and procedures that may be injurious to health if adequate precautions are not taken. It refers only too technical suitability and in no way absolves either the supplier or any user from statutory obligations relating to health and safety at any stage of manufacture or use. Where attention is drawn to hazards, those quoted may not necessarily be exhaustive.

20. This Defence Standard has been written and is to be used taking into account the policy stipulated in JSP430: MOD Ship Safety Management System Handbook.

Additional Information

(There is no relevant information)

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1 Scope

1.1 This Defence Standard (Def Stan) defines the requirements for:

a) The design, manufacture, installation, test and Setting–to–Work of Domestic Hot and Cold Fresh Water (FW) Systems in HM Surface Ships and Submarines.

b) Special FW services and duties which may be associated with various types of craft and functions are also included.

c) Comprehensive guidance on the design calculations for the systems. Sample calculations for both general and special requirements are given in Annex C.

2 Warning

The Ministry of Defence (MOD), like its contractors, is subject to both United Kingdom and European laws regarding Health and Safety at Work. Many Defence Standards set out processes and procedures that could be injurious to health if adequate precautions are not taken. Adherence to those processes and procedures in no way absolves users from complying with legal requirements relating to Health and Safety at Work.

3 Normative References

Documents referred to throughout this Def Stan are listed in Annex A.

4 Definitions

Definitions referred to throughout this Def Stan are Listed in Annex B.

5 Abbreviations

The following abbreviations are used throughout this Def Stan:

AV&B Auxiliary Vent and Blow System

CBRNDC Chemical Biological Radiological Nuclear Damage Control

CV(F) Future Aircraft Carrier

CVS Carrier Vertical Strike

DE&S Defence Equipment and Support

FW Fresh Water

HP High Pressure

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Def Stan 02-728 Issue 3 MCH Mechanical handling Constructive and Hydraulics

MES Maritime Equipment and Systems

MOD Ministry of Defence

NES Naval Engineering Standard

NPSH Net Positive Suction Head

OBU Output Business Unit

OD Outside Diameter

PIPT Platform Integrated Project Team

QAR Quality Assurance Representative

RAS Replenishment at Sea

SDN Service Drawing Number

SSG Structures Support Group

STR Statement of Technical Requirements

SW Sea Water

WC Water Closet

WSC Weapons Storage Compartment

6 Performance Specification

6.1 Drawings

a) Each pipe system covered in this Def Stan for which drawings are required will be specified in the STR. Drawings are to be based on any associated DE&S Platform Integrated Project Team (PIPT) guidance drawings.

b) All drawings are to conform to requirements of Def Stan 05-10 Parts 0-3.

c) Drawings to be supplied by the Shipbuilder will be defined in the STR.

6.1.1 System Diagrammatic Arrangement Drawings

a) System Diagrammatic Arrangement drawings are to show:

1) The layout of the system in accordance with BS 5070 Part 3, with all associated equipments, valves, fittings and pipe runs shown in their correct relative positions, so that the various modes of operation and control of the system can be checked;

2) Associated equipments, valves, fittings and pipe runs as symbols in accordance with BS 1553 Part 1, with a list of symbols used;

3) Pipe sizes, outside diameter;

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4) A list of materials proposed;

5) The relationship to associated systems;

6) Instrumentation and controls;

7) Venting and drainage arrangements;

8) Arrangements for the prevention of backflow, see Annex D;

9) Working and test pressures, see clause 6.12.10;

10) Definition of terminal points and interfaces between Main Machinery Contractor, Contractors and Subcontractors;

11) Tables of calorifiers, pumps, filters and accumulators showing designation, duty and limiting parameters as appropriate.

b) Diagrammatic Arrangements are to be geographically correct in respect of compartment boundaries such as bulkheads, decks, etc. They are also to be as geographically correct as possible in respect of major components connected to or in the system, subject to ensuring that the clarity and basic simplicity of the diagram is not compromised.

c) Drawings are to include the following information:

1) Maximum and minimum water flows, water speeds and pressure losses through each branch pipe;

2) Data Sheets of pipe sizes supporting the above.

d) System Diagrammatic Arrangement drawings are to form Basis Information which is to be kept up–to–date by the Shipbuilder and is to be available to all concerned vessels at all times.

6.1.2 System Ship Arrangement Drawings

a) System Ship Arrangement drawings are to be drawn to scale, superimposed on the hull in plan and elevation, to show the location of the system and components relative to the hull, bulkheads, decks and other items of machinery and equipment.

b) System Ship Arrangement drawings are to indicate the positions and identity of flanged joints, orifice plates, screwed connections, capillary, brazed and welded joints in addition to items 1) to 10) inclusive of clause 6.1.1a).

6.1.3 Equipment Drawings

a) Equipment drawings showing major items of equipment are to be prepared by the equipment manufacturers. Equipments for which drawings are required include:

1) Calorifiers;

2) Pumps;

3) Strainers;

4) Accumulators.

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Def Stan 02-728 Issue 3 b) Equipment drawings are to show:

1) Overall dimensions;

2) Overall Weight;

3) Mounting arrangement and jacking points;

4) General arrangement;

5) Terminal points;

6) Lifting points and position of Centre of Gravity, dimensioned.

7) Maintenance envelope, showing accessibility for maintenance, e.g. rodding points, etc, and space required for withdrawal/replacement of component parts, (see Def Stan 02-302 Part 1(for legacy fits) for Surface Ships and Def Stan 08-103 Part 2 (for legacy fits) for Submarines);

8) Parts List;

9) Assemblies;

10) Sub–assemblies;

11) Circuit Diagrams (mechanical and electrical).

6.2 Materials

6.2.1 Material Selection

a) Any proposals to use new materials not specified in this Def Stan are to be submitted to DES SE Sea-MT for approval

b) Gunmetal is only to be used in Submarines with the specific approval of DES SE Sea-MT.

c) Materials for components are to be selected to reduce corrosion and erosion to a minimum, be non-toxic and consistent with reasonable cost and ease of manufacture.

d) All items used in the construction of Ships FW systems should be of types that do not harbour bacteria.

e) Pipe clips are to be of steel, galvanized in accordance with BS EN ISO 1461.

6.2.2 Fresh Water Storage Tanks

a) FW storage tanks are generally to be built as an integral part of the hull. Where constructed independent of the hull structure in accordance with World Health Organization recommendations, storage tanks are to be of metal or other suitable material.

b) Internal surfaces of FW storage tanks are to be preserved in accordance with Warpaint.

c) Access ladders inside storage tanks are to be of steel, galvanized in accordance with BS EN ISO 1461.

d) Non–ferrous fittings are not to be used in FW storage tanks.

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6.2.3 Accumulators

a) Accumulators are to have an outer steel shell and an inner separator bag of synthetic rubber.

b) Only DES Ships FWE-MES-MCH approved accumulators are to be used.

6.2.4 Pumps

Materials for rotary pumps are given in Def Stan 02-327.

6.2.5 Calorifiers

Materials for rotary pumps are given in Def Stan 02-329.

6.2.6 Valves

a) Materials for valves are given in Def Stan 02-360.

b) Push cocks for supply to cabin, bathroom, workshop and office washbasins, mess draw–off, etc, are to be of chrome–plated brass.

c) In Submarines all in line valves are to be of the ball type.

6.2.7 Strainers

Strainers are to be as specified in the STR and will conform to Def Stan 02-748.

6.2.8 Pipework

a) All FW piping except that specified in clause 6.2.9 is to be pure copper (99%CU) BS EN 1057 (6 bar, 200oC maximum temperature) and Def Stan 02-837. Connections and flanges are to be of gunmetal to Def Stan 02-830 Part 1 (see BR 3013(2) except where clause 6.2.1b) applies.

b) Exposed piping in bathrooms, galleys and cabins is to be chromium plated spec.

6.2.9 Steel Pipework

Sounding tubes, air escapes and sections of suction pipes within FW tanks are to be carbon steel complying with BS EN 10216 Part 2 or BS EN 10217 Part 2, galvanized internally and externally to BS EN ISO 1461. Connecting sleeves and ring flanges are to be of steel complying with BS EN 10028 Parts 1, 2 and 4 and BS EN 10029 (see BR 3013(2)), and galvanised to BS EN ISO 1461.

6.2.10 Screwed Fasteners

a) Materials for screwed fasteners are to be:

1) High tensile aluminium bronze complying with Def Stan 02-833 Part 2 for non-ferrous pipes and fittings only.

2) Steel complying with BS 3692, zinc plated in compliance with BS 7371-12, for diameters up to M18 and BS EN ISO 2081, Zn3 for diameters above M18 for ferrous pipes and fittings.

6.2.11 Jointing

Rubberized cork jointing rings are to be ordered from the manufacturer as pre-cut gaskets to the dimensions given in BR 3013(2) Part 2. Gaskets are not to be coated with jointing paste.

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Def Stan 02-728 Issue 3 6.2.12 Insulation

Thermal insulation is to conform to Def Stan 02-703.

6.3 System General Requirements

6.3.1 General

a) Domestic hot and cold FW systems are to be designed to meet the following military requirements:

1) To deliver the specified quantities of FW with the minimal head loss, noise, and pumping power commensurate with economically sized piping. The installation is to be planned in association with other services to maintain adequate headroom and facilitate future refit work;

2) To ensure that the system will provide and maintain the required degree of water quality in service as specified in BRd 820, this is to include adequate measures to reduce the risk of legionella;

3) FW tank boundaries shall not be shared with other tanks, e.g. fuel, sewage, drains, contaminants;

4) NO toilet, urinal or shower/wash room should be installed over that part of a deck that forms the top of a potable water tank. No drain-line or pipe carrying non-potable liquids should pass through the tank unless a tunnel of acceptable construction is provided. Lines carrying sewage or other highly contaminated liquids should not pass directly over the manhole in the tank or treatment areas.

5) To obtain, on HM Surface Ships, a degree of insurance against action damage by dividing the system and providing storage tanks, circulating pumps, calorifiers, etc, both forward and aft. This will ensure an independent workable system at each end of the ship. On Submarines this duplication is not required;

6) To minimum space and weight requirements;

7) To meet zoning requirements laid down in Def Stan 07-204 Part 1 and Def Stan 08-204 Part 3.

b) The systems are to cater for a daily consumption allowance of 200 litres per day per member of complement (excluding boiler feed) for surface vessels and 90 litres per day per member of complement for Submarines. The allowance for HM Surface Ships is to be supplemented by the requirement for turbine washing, aircraft washdown and ship husbandry (including superstructure washdown), i.e. 50 litres per turbine per day, 500 litres per aircraft per day and 500 litres per day for ship husbandry.

c) The systems are to be designed to conform to the requirements of Def Stan 02-797 Part 4.

d) In HM Surface Ships systems are to be designed to provide a pressure of 0.35 bar at the highest and most remote points and to meet the requirements of any special equipment needing greater pressure. A bridge window washer system is to be fitted capable of providing a minimum pressure of 1.4 bar at the bridge window.

6.3.2 Hot Water System, Services Supplies

6.3.2.1 HM Surface Ships

a) Compartments and services to be provided with hot fresh water in HM Surface Ships include:

1) Bathrooms, WC and Urinals, see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels;

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2) Galleys and associated spaces, see Def Stan 02-121 Parts 1, 2 and 4;

3) Laundries, see Def Stan 02-123 Part 1;

4) Medical and Dental spaces, see Def Stan 02-106 Part 1 – 4;

5) Hangars and flight-deck aircraft service positions, see Def Stan 08-133 Parts 1 and 2;

6) Other compartments fitted with washbasins, see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels, including cabins, see MAP 01-107 Parts 1 & 2 and selected workshops, see Def Stan 02-101 Parts 1 and 2.

6.3.2.2 Submarines

a) In addition to those items listed in clause 6.3.2.1 which are applicable to Submarines, main services to be provided with hot FW include:

1) Sinks, wash-basins and showers;

2) Bibcocks;

3) Electrostatic Precipitators.

6.3.3 Battery Top–up Water (Submarines)

In Submarines, water for battery top–up is to be supplied from the FW system through a demineralizer.

6.4 System Arrangement

6.4.1 Cold Fresh Water in HM Surface Ships

a) Compartments and services to be supplied with cold FW in HM Surface Ships include


2) Dining Halls, see MAP 01-107 Parts 1 & 2;

3) Drinking water coolers and ice cube making machines;

4) Galleys and associated compartments, see Def Stan 02-121 Parts 1, 2 and 4;

5) Laundries and laundry equipment, see Def Stan 02-123 Parts 1 and 2;

6) Medical and Dental spaces, including secondary medical positions, see Def Stan 02-106 Part 1 – 4;

7) Other compartments fitted with washbasins, see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels, including cabins, see MAP 01-107 Parts 1 & 2 and selected workshops, see Def Stan 02-101 Parts 1 and 2.

8) Gas turbine compressor washing tanks, see Def Stan 02-309;

9) Self-cleaning centrifuge header tanks;

10) Desalination plant servicing positions;

11) Filter cleaning station;

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12) Battery charging room;

13) Engineer's test room;

14) Photographic room;

15) Torpedo test and assembly magazine;

16) Hangars and flight-deck aircraft service positions, see Def Stan 08-133 Parts 1 and 2;

17) Citadel cleansing stations, see Def Stan 08-144;

18) Gun mountings;

19) Bridge window washer systems, see Def Stan 02-112;

20) Chemical, biological, radiological, nuclear damage control (CBRNDC) section bases, see Def Stan 07-204 Part 1 and Def Stan 08-204 Part 3;

21) Supply to hot water system.

b) Cold FW for wash-down purposes is required in HM Surface Ships as follows:


2) Galleys, see Def Stan 02-121 Parts 1, 2 and 4;

3) Laundries, see Def Stan 02-123 Part 1.

c) The following are possible users of cold FW in HM Surface Ships on an intermittent basis:

1) Emergency FW supply to sonar cooling system;

2) Spraying for NBC cleansing of missile launcher hoists;

3) Spraying for NBC cleansing of missile magazines;

4) Cleansing stations, where not used as bathrooms;

5) Boiler external washing;

6) Boiler acid cleaning;

7) Gas turbine intake filter washing;

8) Topping-up diesel engine FW cooling systems;

9) Filling and topping-up air conditioning chilled water system;

10) Filling and topping-up of magazine spraying systems controlled by quatzoid bulbs;

11) Domestic water boiler;

12) NAAFI vending machines;

13) Motor boat filling (upper deck).

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d) Essential services include:

1) Medical and Dental spaces, including secondary medical positions, see Def Stan 02-106 Part 1– 4;

2) Galleys and associated compartments, see Def Stan 02-121 Parts 1, 2 and 4;

3) Drinking water coolers;


5) Bathrooms used as cleansing stations, see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels;

6) FW cooling to guns.

6.4.2 Cold Fresh Water in Submarines

a) For Submarines, selected items listed in clause 6.4.1a) are applicable (where appropriate) and main services to be supplied with cold FW will normally include:

1) Domestic water boiler;

2) Water heaters;

3) Flushing of shaft seal;

4) Demineralizers;

5) Pyrotechnic lockers;

6) Sink at Oxygen generators;

7) Escape compartments for filling emergency drinking water storage tanks;

8) Where a cooled drinking water unit is not fitted in or adjacent to the sick bay, a drinking water tank is to be provided.

6.4.3 Provision of Washbasins and Showers

For scale of allowance of washbasins, showers and baths, see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels.

6.4.4 System Requirements

a) The system is to comprise storage tanks with associated pumps, suction, discharge, filling and transfer arrangements. The pumps are to discharge direct to the FW main.

b) Two FW storage tanks, or groups of tanks, are to be fitted, one forward and one aft. The precise number and size of tanks are to suit the space available in each class of ship.

c) The total tank capacity is to be as defined in clause 6.6.1a).

d) A diagrammatic arrangement of a typical Domestic Cold Water System for a HM Surface Ship is shown in Figure 1.

e) Suction and delivery valves, with the necessary connections, are to be fitted to enable the pumps to deliver FW to the FW main and to transfer water within the ship.

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Def Stan 02-728 Issue 3 f) The system is to be a continuous running pump system, with the minimum number of pumps operating

at a time. The pumps are to be capable of supplying the services in all conditions with little pressure variation over the delivery range. At least two pumps are to be installed, one at each end, with only one running at a time, see clause 6.11.2m). Adequate arrangements are to be made to provide against pumps overheating during periods of no discharge. Start/Stop facilities are required:

1) Locally, adjacent to the pumps;

2) Remotely, in or adjacent to Damage Control HQ to permit Starting and Stopping of pump(s) in CBRNDC State 1.

g) The suction pipework from the FW storage tanks to the cold water pumps is to be arranged so that either pump associated with a group of tanks can draw from any tank in that group.

h) The suction pipework is to include the necessary isolating valves, non–return valves and a 1.5 mm diameter aperture size pump suction duplex strainer to conform to Def Stan 02-748.

i) The discharge pipework from each pump should include an isolating valve and a non–return valve which is to be fitted as close to the pump as possible.

j) Pressure indicators are to be fitted at the following positions:

1) At each pump suction and discharge. These indicators are normally provided as part of pump;

2) On the FW main near the junction with the pump risers;

3) At the highest points in the system.

k) Local and remote reading pressure indicators are to be supplied and fitted in the FW main for surveillance equipment. The remote position is to be in the Ship Control Centre (SCC).

l) Hose connections are to be fitted on the suction and delivery sides of the FW pumps for use with a portable pump in an emergency.

m) Flexible assemblies fitted in the system are to conform to the requirements of Def Stan 02-797 Part 4.

n) A filling and transfer line is to be fitted throughout the length of the ship to connect the various groups of FW tanks to the desalination plant and FW filling deck connections. The filling and transfer line will be used for supplying desalinated water to the FW storage tanks and also for supplying the tanks with water from the deck connections and for transferring water from one group of tanks to another. In ships with steam boilers and more than one desalination plant the filling lines between the plants and the feed tanks, and the plants and the FW tanks, are to be arranged so that one plant can distil to feed tanks and one to ship’s tanks independently of each other.

o) The FW main supply from the storage tank is to be led forward and aft throughout the vessel, generally on the lowest continuous access deck, with branches led to the various services, including the hot water calorifiers. Wherever possible a ring main is to be provided with the pumps discharging into the cross–connections. In the case of the smaller vessels where a ring main may be impracticable, a main line and spur type of system is permitted.

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Figure 1 - Typical Domestic Cold Water System for HM Surface Ships

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Def Stan 02-728 Issue 3 p) Supplies of FW are to be maintained to essential services when the remaining services have been

isolated, due to an emergency or for rationing. The isolation is to be achieved by the closing of a limited number of valves on the FW main. The essential services include:

1) Medical and Dental spaces, see Def Stan 02-106 Part 1– 4;

2) Galleys and associated spaces, see Def Stan 02-121 Parts 1, 2 and 4;

3) Drinking water coolers;


5) Bathrooms used as cleansing stations, see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels;

6) FW cooling to guns.

7) Sonar equipment cooling.

q) Strainers with a 1.5 mm diameter mesh are to be fitted as required before special items of equipment (e.g. the bridge window washer system where one strainer is fitted in the common main that supplies all window washers). Non–concussive push cocks are to be used as isolating valves to individual window washers.

r) Isolating valves are to be fitted in the FW main so that supplies can be maintained if sections of the main are damaged.

s) Branches are to be fitted with lockable isolating valves close to the main. Valves are to be provided with service pattern locks as necessary.

t) FW leads are to be arranged so that they can be readily drained and emptied. Branches exposed at atmospheric temperatures are to be arranged so that they can be isolated and drained if temperatures below 0°C are expected or encountered. For this purpose, isolating and drain valves are to be fitted.

u) In places where water may remain after the system has been drained (see clause 6.4.4t), screwed drain plugs are to be fitted. A light alloy or nickel silver tally plate, engraved ‘FROST PLUG’ is to be fitted in a clearly visible position at each plug. Half a complete set of plugs is to be provided to the ship as spares.

v) Small air chambers are to be arranged, at the top of each riser and at the end of horizontal lines, to prevent water–hammer.

w) Automatic air release units are to be as specified in clause 6.10.4. The detailed requirements for air removal are given in clause 6.11.15.

x) Flexible assemblies fitted in the system are to conform to the requirements of Def Stan 02-710 (for legacy fit) and Def Stan 02-797 Part 4.

y) Emergency leads from the FW main, are to be led to the vicinity of cabinets normally cooled by tepid water (see clause 6.4.6).

z) Cross connections between FW and Sea Water (SW) systems are not permitted. Where it is necessary to supply fresh and sea water alternatively to equipment, or to supply FW to certain auxiliary machinery, the FW is to be supplied by means of a hose, connected to the supply end only or an open funnel filling connection is to be used.

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aa) Where the required system total head exceeds 4 bar or 90% of the maximum head available from the

cold FW pump selected, whichever is the lower, a boost system, supplied by a continuously running pump, self–priming as necessary, is to be provided to serve the higher outlets. The most convenient point to install the boost pump is to be selected so as to be close to the maximum demand on the boost circuit and to suit the ship’s arrangement. The point selected is to serve all outlets on the top decks and is to be suitable for use with any one cold water pump out of service. In large ships it may be necessary to fit more than one boost pump.

bb) The boost system is to be provided with a return to the FW main, with orifice control, to ensure a continuous flow through the boost pump thus providing a cooling circuit. The boost system is to be provided with isolating valves, non–return valve, strainer and pressure indicators on either side of the pump. See Figure 1.

6.4.4.1 Submarines

a) The system is to comprise a distribution main supplied from two or more FW storage tanks pressurized either from the Auxiliary Vent and Blow System (AV&B) or a continuous running pump system. A separate weapons spray tank is to be fitted.

b) One group of storage tanks is to be fitted. The precise number and size of tanks are to suit the space available in each particular Submarine.

c) The total tank capacity is to be as defined in clause 6.6.1.

d) A diagrammatic arrangement of a typical Domestic Cold Water System for a Submarine is shown in Figure 2.

Figure 2 - Typical Domestic Cold Water System for Submarines

e) The normal system operating pressure is to be 2 bar.

f) Supply to the storage tanks is to be from the Submarine’s desalination plant via the feed transfer and FW filling system or as specified in the STR.

g) The system is to permit all tanks being filled from an outboard source by hose, through an inboard hose connection situated near a hatch. This connection is to be fitted with a ball type stop valve and strainer. A FW filling control station is to be sited in a convenient position.

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Def Stan 02-728 Issue 3 h) Arrangements are to be made so that the feed water may be used to augment the FW supply.

i) The system is to be so arranged that one storage tank can supply water to the main while the other is being filled from the FW filling line.

j) A 3 mm diameter hole is to be drilled in the lowest pipework downstream of each pyrotechnic locker flooding isolating valve to indicate any leakage past the isolating valve.

k) The forward weapons spray tank is always to be full and to be capable of being readily pressurized. The system operating pressure being indicated in the STR.

l) Facilities are to be provided for directly connecting a shore FW/SW supply to the spray system as well as SW back–up from the High Pressure (HP) bilge system or a suitable alternative system.

m) The portion of piping within the containment boundary is to be suitable for testing to containment pressure. Alternatively the system is to be fitted with readily accessible isolating valves at and outside, but as close as is practicable to, the containment boundary.

n) Valves, tested to the full bulkhead design pressure, are to be fitted on both sides of penetrations of main and escape bulkheads and on the outside of containment boundary penetrations.

6.4.5 Hot Fresh Water Systems


a) One or more hot water systems are to be installed. Each system is to comprise a calorifier, an accumulator, circulating pump, valves and associated fittings. Each system is to be pressurized by the cold FW supply.

b) For HM Surface Ship' calorifier capacity, see clause 6.11.10b).

c) Each hot water system is to be arranged as a ring main with branches to the various outlets. The length of branches to outlets are to be kept to a minimum to limit the wastage of hot water.

d) Where more than one hot water system is installed it may be advantageous to cross–connect the ring mains to provide a safeguard against an emergency condition when either calorifier is out of action. Each cross–connection is to be provided with a locked–shut isolating valve.

e) A diagrammatic arrangement of a typical Domestic Hot Water System for a HM Surface Ship is shown in Figure 3.

f) The calorifiers are to be supplied with water by a branch from the cold FW main, led to the bottom of the calorifier and fitted with an isolating valve and non–return valve at the calorifier. The hot water outlet pipe is to be connected to the crown of the calorifier.

g) The accumulator is to be located adjacent to the calorifier and connected to the cold water supply just before it enters the calorifier (see clause 6.10.1a).

h) During periods of low demand, hot water is to be circulated around the ring main. The circulation is to be sufficient to ensure that the temperature difference between the calorifier outlet and return is not in excess of 5°C.

i) For small systems and when there is adequate vertical lift, a thermo–siphon system will provide the required circulation.

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Figure 3 - Typical Domestic Hot Water System for HM Surface Ships

j) For larger systems a circulating water pump is to be provided in the return piping which is to be connected to the bottom of the calorifier. A non–return valve and pump suction and discharge isolating valves are to be provided. A bypass is to be fitted around the circulating pump for natural circulation in the event of pump failure. The procedure for determining if a circulating pump is required is given in clause 6.11.9c).

k) The number of hot water systems and hence calorifiers is to be decided by combining the hot water requirements into convenient groups. Each individual calorifier’s share of the total heating capacity is to be in proportion to the design flow rate of that calorifier’s hot water system.

l) The storage capacity is to ensure that the temperature of the hot water outlets does not drop below 60°C 50°C during a peak demand from a system initially at above 63°C 65°C. Storage capacity calculations are given in clause 6.11.12.

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Def Stan 02-728 Issue 3 m) The general requirements for the cold water systems given in clauses 6.4.4q) to 6.4.4w) apply to hot

water systems.

n) Hot water boost systems should be avoided because pumps are large and costly, therefore use local electric heaters supplied from the cold water system to provide hot water at a high level within the ship. Where hot water boost pumps are essential, their design and installation is to be based on the same practice as the cold water boost pump, see clauses 6.4.4aa) to 6.4.4bb).

o) Local water heaters will always be powered by electricity.

6.4.5.2 Submarines

a) One hot water system is to be installed consisting of a calorifier pressurized from the cold FW supply.

b) A diagrammatic arrangement of a typical Domestic Hot Water System for a Submarine is shown in Figure 4.

Figure 4 - Typical Domestic Hot Water System for Submarines

c) The calorifier, which is to be electrically heated, is to have a storage capacity of 0.55m3 or as indicated in the STR.

d) The hot water system is to be in the form of a ring main with natural thermo–siphon circulation. Branches are to be taken from the supply side only. A non–return valve is to be fitted in the return line to the calorifier.

e) The calorifier is to be capable of supplying water at a temperature of 71°C to meet a flow rate of 4.5 litres per hour per member of complement or as specified in the STR.

f) The heating capacity of the calorifier is to be given and include adequate capacity for those items listed as a minimum as in clause 6.3.2.2.

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g) Penetration of containment and escape bulkheads by the hot water system is to be avoided by the use

of local electric water heaters supplied by the cold FW main.

6.4.6 Emergency Fresh Water Supply to Sonar Cooling System

On some HM Surface Ships an emergency FW supply is required for the Sonar Cooling System. Hose connections with lockable valves and portable hoses to connect between the Domestic Cold Water System and a similar connection on the Sonar Cooling System is to be provided for the supply and similar connections for the return between the Sonar System and the Filling/Transfer Main. These connections are in accordance with the requirements of Def Stan 02-102 Part 1 and Def Stan 08-159 Part 2.

6.5 Desalination Requirements

6.5.1 General

a) In HM Surface Ships and Submarines the desalination plants are to conform to the requirements of BR 1333 and BRd 820 Chapter 4. They will generally be of the following types:

1) Evaporators;

2) Flash distillation plants;

3) Reverse osmosis.

b) FW produced using the Reverse Osmosis (RO) is to be re-mineralised and chlorinated downstream of any desalination plant in accordance with the requirements of BRd 820 Chapter 4.

c) An auto chlorination unit is to be fitted downstream of the desalination plant.

d) RO and Low Pressure (LP) plants are to have a dedicated sea suction sited forward of, and on the opposite side of, the ship to that of Bilge and Sanitary discharges.

e) For all RO plant installations the SW supply shall be filtered through a suitably sized sand filter (verified by design calculations). The sand filter will have automated backwashing and air elimination included.

f) In emergency, a facility should be made to allow the SW feed to the RO plants to be taken from the ships High Pressure SW System.

6.5.2 Submarines

An additional allowance of water is to be made for make–up of the primary and secondary propulsion system.

6.6 Fresh Water Storage and Filling

6.6.1 Storage Capacity

a) Provision is to be made for the following minimum quantities of FW to be stored onboard all HM Surface Ships and Submarines:

1) All HM Surface Ships:

i) 1.0m3 per person of complement

ii) 2.5m3 per aircraft (where applicable);

iii) 2.5m3 ships husbandry;

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iv) 0.25m3 per turbine - ship and aircraft (where applicable).

2) Submarines:

i) 0.23m3 per person of complement in or as indicated in the STR:

b) Consideration must be given to increasing the levels quoted for HM Surface Ships that will spend significant periods of their operational service close in shore where water production plants cannot be operated effectively.

6.6.2 Storage Tank Arrangement


a) FW tanks for aviation arrangements are to be designed to the requirements of Def Stan 08-133 Parts 1 and 2.

b) Generally, storage tanks are to be strongly constructed, well stiffened and fitted with divisional plates to prevent surging and thumping when the ship rolls heavily. The tanks are to be arranged so that air pockets will not form during filling and such that the water will level itself as fast as it is delivered; escape and limber holes being cut in beams, frames, etc, as necessary to facilitate filling and draining. Where air pockets are unavoidable, an additional air escape may be fitted.

c) The internal structure of each tank is to allow ready access to all parts of the tank for preservation, by abrasive blasting and painting and for inspection and cleaning.

d) Welding is to conform to Def Stan 02-706.

e) For tank preservation see clause 6.12.8.2a).

f) A high standard of inspection of all welded joints in FW tanks is essential to maintain FW purity, see clauses 6.12.2b) and c). Where the requisite standard of inspection cannot be met, then FW tanks are to be separated from other tanks containing SW or oil by means of watertight coffer-dams.

g) For calibration of tanks see clauses 6.12.9.

h) Access to tanks is to be provided by manholes fitted with raised coamings and watertight covers. The covers are to be secured by through bolts or studs in accordance with the latest approved practice. For Submarine applications, the latest approved practice, e.g. flush manholes, is also to be followed.

i) Ladders in FW tanks are not to be coated but are to be galvanized, see clause 6.2.2c).

j) Piping, gearing etc, of any description are not to be led through the tanks except when required for the operation of the FW system. For restriction on the use of non–ferrous fittings in tanks see clause 6.2.2d).

6.6.2.2 Submarines

Three FW storage tanks are usually fitted in Submarines. Two of the tanks being for domestic FW, the other being dedicated to the weapons stowage compartment spray system.

6.6.3 Filling Arrangements


a) Provision is to be made for receiving FW through screwed deck connections and elbow adaptors from shore, from water–boats alongside and from water–carriers during Replenishment at Sea (RAS). Provision is also to be made for the supply of water to ships alongside or in company.

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b) Food-safe 'Blue' potable water hoses must be used for embarking FW. Each class of vessel will have

an allocation of 'Blue' FW hose. Details of NSNs and applicability to vessels can be found in BRd 820 Chapter 5.

c) The filling system is to be designed to enable the following pumping rates to be met:

1) Ships of Frigate/Destroyer size and above 100m3/h;

2) Ships below Frigate/Destroyer size 50m3/h.

d) In HM Surface Ships a minimum of four shore filling connection points are to be fitted, sited as follows:

1) For ships of length between 109 (100)m and 131 (149)m:

i) Two connections between 40m and 49m from the forward end, one port and one starboard;

ii) Two connections between 40m and 49m from the aft end, one port and one starboard.

2) For ships of length between 150m and 213m:

i) Two connections between 35m and 53m from the forward end, one port and one starboard;

ii) Two connections between 35m and 53m from the aft end, one port and one starboard.

e) In ships less than 100m in length the provision of two points is acceptable, providing that they are sited near to the centre line, one forward and one aft within the ranges specified in clause 6.6.3.1d), with direct access across the deck from either side.

f) Storage tanks are to be filled via the filling and transfer line, through deck connections sited as specified in clause 6.6.3.1d). Each deck connection is to be arranged to take an adaptor fitted with two 65mm female instantaneous hose connections to SDN 000 819 097/1-2.

g) In multi–spot ships, the deck connections are to be fitted in the deck or ship side in the positions specified in clause 6.6.3.1d), and cross–connected. Leads are to be taken from the cross–connections to the filling and transfer line.

h) For RAS, deck connections are to be readily accessible to the RAS areas. Each deck connection is to be provided with an adaptor to SDN 000 819 098/1-3 to take a 165mm flange.

i) In order to avoid the risk of excessive pressure in the FW storage tanks during filling operations, filling funnels are to be fitted above the crown of each storage tank. Each filling funnel is to be filled with a light alloy cover provided with a locking arrangement. The filling and transfer main is to discharge into the filling funnels. A ball/plug valve, selected from Def Stan 02-360, is to be fitted in the filling pipe immediately above the filling funnel and also at the tank top. The pipe below the filling funnel to the tank is to be at least one size larger than the filling and transfer main.

j) Aerating roses are to be fitted on the filling line within the tanks.

k) Each FW tank is to be fitted with a continuous remote level monitor, indicating at the ship's control console and the FW filling station. The sounding tube is to be used for checking the level gauge as necessary.

l) Special precautions are to be taken to ensure that the hoses used for filling the storage tanks, and the tanks themselves are thoroughly clean when taking water on board, (see BRd 820 Chapter 5).

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Def Stan 02-728 Issue 3 6.6.3.2 Submarines

a) Normal supply to the storage tanks is to be from the desalination plant via the feed transfer and FW filling systems. Where FW tanks are sited adjacent to the Weapons Storage Compartment (WSC) they are not to be supplied directly from the desalination plants unless the water is first cooled.

b) The system is to permit all tanks (excluding emergency cooling cylindrical and jacket tanks) being filled from an outboard source by hose, to be through an inboard hose connection situated near the engine room hatch. This connection is to be fitted with a ball type stop valve and strainer. The FW filling control system is to be sited at the position specified in the STR.

c) Food-safe 'Blue' potable water hoses must be used for embarking FW. Details of the hoses can be found in BRd 820 Chapter 5.

d) Arrangements are to be made so that feed water may be used to augment the FW supply.

e) The system is to be so arranged that one storage tank can supply water to the main while the other is being filled from the FW filling line. The tank to the WSC spray system is always to be full.

f) Each tank is to be fitted with a remote reading contents gauge indicating at the FW filling station. The tank supplying the WSC spray grid is to be fitted with a low-level alarm.

6.6.4 Filtering

a) FW from UK Base ports is tested as part of Project Aquatrine and, unless otherwise stated, is deemed fir for consumption. Other UK ports are likely to be tested in a similar manner, though enquiries on quality should be made via the port agent if there is any doubt. Refer to BRd 820 Chapter 5.

b) In accordance with requirements of BRd 820 and following recommendation from NMOH, FW embarked whilst in a foreign port where water quality is suspect or from undocumented sources should be filtered for Cryptosporidium and other gut parasites. As a result of this a minimum of one filling point should be fitted with a means of filtering the embarked FW. The filtration must be rated to 1 micron absolute and have suitable method of back flushable pre-filtration in order to reduce fouling of the 1 micron filter.

c) Where existing vessels do not meet the requirements of this, a portable FW Embarkation Unit (FWEU) has been provided. The portable FWEU is detailed in BRd 820 and is to be used as advised by NMOH in foreign ports where water quality is suspect of from undocumented sources. The portable Filtration Units are designed to remove gut parasites only and have no effect on bacteria and viruses. Therefore, FW is to be chlorinated in accordance with the procedures in BRd 820 Chapter 4.

d) Food-safe 'Blue' potable water hoses are to be used with Portable Filtration Unit.

e) Existing Submarines are not scaled to carry Portable Filtration Units. If there are any concerns over the quality of FW to be embarked, demineralised water id to be embarked as an alternative. Reference should be made to BRd 820 Chapter 5 if embarking de-mineralised water.

f) Future Submarines are required to have permanently fitted FWEUs.

6.6.5 Sterilization

a) Automatic chlorine dosing units are to be fitted to facilitate the sterilization of the FW in the storage tanks and the system to ensure levels of free chlorine are maintained throughout the system as laid down in BRd 820 Chapter 4.

b) Water purifiers may be fitted between the desalination plant and the filling and transfer main for use when unavoidably producing in potentially polluted waters; see BRd 820.

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c) Former distinctions between the standards required for drinking and washing water should not be

maintained.

d) Vessels are to be fitted with by-passable, automatic chlorine dosing units at embarkation points to ensure levels of free chlorine are maintained in accordance with BRd 820 Chapter 4.

6.6.6 Sounding Tubes

a) In HM Surface Ships a sounding tube is to be fitted to each FW tank as a back-up to electronic, remote monitoring, and is to be 60.3mm pipe size which is of suitable bore to pass the MOD standard sounding tape. The pipe is to be similar to that used for air escapes (see clause 6.2.9). The sounding tube may be combined with one of the tank’s air escapes in which case the tube is to be perforated within the tank just below the crown to provide an open area equal to that of the air escape. See SDN 003 503 642 and SDN 003 503 703.

b) The sounding tube is to be vertical and is to extend to within 100mm of the bottom of the tank. In order to prevent damage to the tank coating, the bottom of the sounding tube is to be sealed. Perforations around the circumference of the tube are to be made to permit entry of the water.

c) The upper end of the sounding tube is to be provided with a locked screw cap and is to be fitted in the vicinity of the filling funnel. Where practicable, sounding tubes are to be arranged alongside bulkheads, etc, in order that their upper ends may extend permanently about 300mm above the deck. Elsewhere they are to be fitted with locked watertight deck plates.

d) Sounding tubes are to be hot–dip galvanized internally and externally to BS EN ISO 1461 after all welding and machining has been completed.

e) Sounding tubes are not fitted in Submarines where reliance is placed on remote monitoring instrumentation.

6.6.7 Air Escapes

a) Two air escapes are to be fitted at the highest position in each tank, the two positions being as remote from one another as can be arranged. For tanks of capacity 75 tonne or more the pipes are to be 60.3mm outside diameter (OD) pipe size; for tanks under 75 tonne capacity the pipes are to be 42.4mm OD pipe size. Where a filling funnel is not used and the tank is filled directly, then it must be ensured that the total area of the air escapes is not less than the tank filling pipe.

b) Materials for air escape pipes are given in clause 6.2.9. The pipes are to conform to BR 3013(2), Part 2 and generally are to have a wall thickness of 3mm. From inner bottom to just above the floor plates in machinery compartments, the pipes are to have a wall thickness of not less than 10mm.

c) Air escape pipes are to terminate in a ‘goose neck’ within the gas citadel and at least 2m above the RED RISK ZONE. The goose neck is to be fitted with a fixed perforated closure and led clear of fuel oil air escapes. Air escape pipes are not to terminate in living spaces unless unavoidable.

d) Care is to be taken to ensure that air escape pipes from FW tanks are not combined with air escapes from any other tank.

e) Air escape pipes are to be led as directly as possible; pockets and long horizontal portions are to be avoided. Pipes are not to penetrate any main transverse watertight bulkhead.

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Def Stan 02-728 Issue 3 6.7 Pump Selection

6.7.1 General

a) The information in clauses 6.7.2 to 6.7.6 applies to pumps for HM Surface Ships only.

b) Pumps are to conform to Def Stan 02-327.

c) Generally, electric motor driven centrifugal pumps are to be fitted, with self-priming where required, for the distribution of FW throughout the ship.

d) For number of pumps to be fitted, see clause 6.11.2m).

e) For operation of pumps in CBRNDC State 1, see BR 2170 series.

6.7.2 Cold Water Pump

a) Where system parameters allow, ideally the cold water pump is to pressurize both the cold and hot FW systems.

b) The total pressure is inclusive of a maximum suction lift of 7.6m and allowance is to be made for a minimum gauge pressure of 0.35 bar at the highest point, or 1.40 bar for Bridge windows whichever is the greater. Friction losses are to be added when assessing what height the pumps can be used to supply.

c) It is possible to obtain pumps with non–standard impellers to give modified performance.

6.7.3 Cold Water Boost Pump

a) If it is necessary to use a pump for boost duty, the pump selected is to be of the self–priming type so as to reduce the period of running with no cold water feed, in the event of a temporary failure of the main cold water system.

b) Consideration is to be given to fitting an electrical cut–out on the boost pump to be initiated by lack of water at the suction.

6.7.4 Hot Water Pump

a) The hot water pump is to provide a circulation round the ring main during periods of low demand to limit the temperature drop between the calorifier outlet and return to about 5°C.

b) Requirements for calculating the capacity of the hot water pump are given in clause 6.11.9c).

c) A pump of simple design, having a continuously falling head/quantity characteristic, preferably fairly ‘steep’ to maintain a re–circulated flow at peak periods, is adequate for the circulating duty. At peak periods the pressure drop in the ring main may exceed the pressure available from the hot water circulating pump. In these circumstances there will be no need for circulation of water but the circulating pump is to be capable of operation for relatively long periods under this ‘run out’ condition, during which it may have a very low Net Positive Suction Head (NPSH) available.

6.7.5 Hot Water Boost Pump

The use of a hot water boost pump is to be avoided by using local electric water heaters, supplied direct from the cold water system, (see clause 6.8.3b)).

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6.7.6 Pump Protection

a) If a cold water pump is allowed to continue to run when no fluid is passing through it overheating may result. A continuous flow of water sufficient to cool the pump can be maintained by the use of a leak–off from the pump supply.

b) With the use of a leak–off there is a continuous flow for which allowance must be made when selecting the pump. An orifice plate is placed in the return line from the pump discharge to the storage tank to limit the pressure of the cooling water entering the storage tank, in the case of a boost pump, from the pump discharge to the supply main.

c) The orifice plate is to be sized as follows:

1) Determine from the pump performance data the minimum flow necessary to protect the pump. Use this flow to establish the friction loss in the return piping from the orifice to the storage tank.

2) Use the approximate formula: d = 10.50 QH

Where d = orifice bore (mm)

Q = flow (m3/h)

H = total head across orifice (m).

d) When any specific pump has been selected, a check is to be made on the manufacturer’s characteristic curves to ensure that the electric motor supplied with the pump will not be overloaded when the pump runs out on its characteristic.

6.8 Calorifiers

6.8.1 Types of Equipment

a) The types of equipment considered are:

1) Domestic calorifiers;

2) Calorifiers, for individual or special services, for use in isolated positions and for emergency use.

b) Selection of calorifiers is discussed in clause 6.11.10.

6.8.2 Heating Capacity

a) The capacity of the calorifier in:

1) HM Surface Ships are to meet as a minimum the requirements of clause 6.11.10b);

2) Submarines are to meet as a minimum the requirements of clause 6.3.2.2.

6.8.3 General Requirements

a) All calorifiers are to conform to the relevant requirements and design data given in Def Stan 02-329 and fitted as required in clause 6.4.

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Def Stan 02-728 Issue 3 b) Isolated positions which cannot conveniently be serviced by the hot water system are to be supplied

by individual electric water heaters. Individual electrical water heaters are also required in medical compartments for emergency use, see Table 1.

Table 1 - Scale of Electric Water Heaters

Ship Compartment over 1300

1300 - 801

800 - 501

500 - 301

under 301

Location

Capacity (m3)

Heat Input (kW)

0.068 0.068 - - - 3 Sterilizing Room - - 0.023 0.023 - 2 Treatment Room 0.023 - - - - 2 Emergency Operating Theatre or Station

0.023 0.023 0.023 0.023 - 2

c) A preferred range of other calorifiers is shown in Table 2.

Table 2 - Range of Alternative Calorifiers

Capacity (m3) Heat Input (kW) 0.023 2 0.068 14 0.113 10

d) Steam/water mixers may be used where specified in the STR and provided non–return valves are fitted in the steam and cold water supply lines.

6.8.4 Submarines

a) In Submarines, the hot water tank is to be electrically heated and thermostatically controlled to limit the water temperature to 71°C. The tank is to have a storage capacity of 0.546m3 and a heating capacity of 34 kW. This is equivalent to a duty of 0.0045m3 per hour per person of complement. The capacity and duty of the hot water system may be varied due to other constraints and reference is to be made to the STR.

b) Heating supplies are to be controlled by thermostats sited in the vessel’s hot water calorifier or tank.

6.9 Drinking Water and Cooled Fresh Water

6.9.1 Emergency Drinking Water

a) In HM Surface Ships emergency drinking water storage is to be supplied using plastic 20 litre cans (NSN 0262/7240-99-120-7251), which are filled and maintained when a ship is at action station, as follows;

1) 160 litres in each First Aid Post;

2) 60 litres in each Engine and Boiler Room;

3) 20 litres in each Auxiliary Machinery Room;

4) 80 litres at each Fire Party Posts;

5) 260 litres in the vicinity of the galley on all major vessels;

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6) 160 litres in the sick bay and emergency operating positions;

7) 160 litres on the bridge;

8) In minor vessels, emergency FW cans are to be fitted where space permits.

NOTE First Aid personnel, closed up at their Action Stations, will carry personal 2 pint water bottles, NSN 8465-99-973-6972, to provide an immediate supply of FW for first aid.

b) Where a cooled drinking water unit is not fitted in or adjacent to the sick bay, adequate stowage for drinking water in 20 litre plastic cans is to be provided.

c) In Submarines emergency FW tanks complete with contents gauges are to be fitted in each escape compartment and are to be of sufficient capacity to provide 0.6 litre per day per person for the entire crew for seven days. For guidance on the capacity or the source of supply, reference should be made to the STR and the current recommendations of the Standing Committee on Submarine Escape and Reserve (SCOSER).

6.9.2 Drinking Water Coolers and Ice Making Machines

a) In HM Surface Ships, self–contained drinking water coolers and ice making machines are to be provided. These are to be of the on-demand type and should not contain reservoirs of water.

b) In Submarines a drinking water cooler is to be provided in the main machinery space and a mineral dispenser, capable of dispensing both soft drinks, cooled water and ice, is to be provided in the crew quarters. The coolers are to be cooled by the Submarine’s chilled water system. The water cooler and ice maker are to be of the on-demand type and should not contain reservoirs of water.

6.9.3 Cooled Fresh Water

a) In ships fitted with a large photographic section, cooled FW is to be supplied to the sinks in the developing and printing rooms. For this purpose a cooled FW tank is to be located in, or close to, the section and supplied from the cold water system through a ball or plug valve. Refrigerant from the ship’s refrigerating machinery is to be circulated through a coil in the tank.

b) A cooled FW unit is to be provided for small photographic sections such as in survey vessels as required.

6.10 Auxiliary Components

6.10.1 Accumulators

a) An accumulator is to be fitted to each hot water system to absorb any increase in liquid volume due to thermal expansion during periods of low demand. Normally the accumulator should be of the hydro–pneumatic type consisting of an outer shell and an inner separator bag pre–loaded with air. Pre–loading arrangements are to be provided on the basis that the air will be supplied by a foot pump through a Schraeder valve connection on the accumulator. Alternatively, on Submarines, a pressure relief valve is to be fitted to the hot water tank and set relative to the appropriate system operating pressure.

b) The procedure for sizing the accumulator is given in clause 6.11.14.

c) Units currently available are given in Table 3.

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Table 3 - Range of Accumulators

Capacity Where Fitted Reference 0.0045m3 SSN IPC FP/17 0.009m3 SSN PIL FP/2 0.035m3 SSN

d) Alternatively, a DE&S FEW-MET RA standard 0.022m3 Chilled/Hot Water Air Conditioning System ‘Feed and Expansion Tank’ may be used without the float level switch.

6.10.2 Submarine Tank Air Pressure Charging Equipment

a) When pressurized from the AV&B System, Submarine FW tanks are to be fitted with combined vent and blow cocks or inboard vents only, depending upon the system arrangement.

b) Reduced pressure air for blowing the tanks is taken from the HP air ring main cross–connection via two reducers arranged in series to give a minimum working pressure as determined in clause 6.11.6e).

c) A pressure indicator with a range of 0 to 15 bar is to be fitted between the reducers. A pressure indicator with a range of 3.5 bar and a relief valve set at 2.4 bar in Submarines.

6.10.3 Pipework

Piping and fittings, connections/flanges, screwed fasteners and jointing are to be selected from the standard ranges given in BR 3013(2), Part 2.

6.10.3.1 Steel Piping

a) Lengths of steel piping are to be connected together by one of the following methods:

1) Pipe sizes below 48mm are to be fitted with screwed sleeves. Long screws, bends and springs are to conform to BS EN 10255, to allow for parallel screwing;

2) Pipe sizes 48mm and above are to be fitted with welded ring flanges to BR 3013(2) Part 2. Flanges are to be welded prior to galvanizing. Where space precludes the fitting of flanges, pipes may be connected by double welded sleeves.

6.10.3.2 Non-Ferrous Piping

a) Lengths of non-ferrous piping are to be connected together by one of the following methods:

1) Pipe size 54mm and below:

i) Capillary fittings to BR 3013 Part 2 and BS EN 1254 Part 1;

ii) Screwed unions for pipe sizes up to 35mm;

iii) Compression fittings to BS EN 1254 Part 2, type A for pipe sizes up to 22mm. Fittings are to be of non-manipulative type only. They are not to be used in the following applications:

I) Terminal connections to equipment likely to be broken and remade (a capillary fitting is recommended in this case);

II) Compartments where equipment would be damaged if subjected to accidental flooding or spraying, such as magazines, electrical equipment rooms and compartments which are not normally manned at sea.

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2) Pipe sizes above 54mm are to be fitted with flanges to BR 3013(2) Part 2;

3) For Submarines, Pipe Fabrication Charts are to be prepared by the shipbuilder and agreed with DE&S PIPT.

6.10.4 Air Release Units

a) Automatic air release units, or manual as may be required, are to be fitted at the highest points of the main piping system and the vent pipes are to be led to convenient drainage systems in a manner which enables water leakage to be readily noticed. The movement and normal trim of HM Surface Ships must be considered in the detailed pipe layout. The actual installation is likely to follow deckhead lines without regard to the optimum aim of self venting design (i.e. a minimum of high points). These requirements are not applicable to Submarines, where FW systems are pressurized by air and air release devices are not fitted.

b) Typical air release arrangements for fitting at the highest points in the main piping system, are given in clause 6.11.15.

c) A typical automatic air release valve is shown in Figure 5.

Figure 5 - Typical Automatic Air Release Valve

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Def Stan 02-728 Issue 3 6.11 System Details

6.11.1 Introduction

Clause 6.11.2 gives information on factors affecting the detail design of hot and cold FW systems which must be considered when carrying out the calculations described in Annex C.

6.11.2 Hot and Cold Water Systems

a) A line diagram is to be prepared for the complete cold water system envisaged, showing all branches with the number of each size of outlet shown on each branch.

b) The distribution of the design water flow is to be allocated to each section of piping. The water flow in any section of pipe will equal the flow discharged by the number of outlets downstream of that section, multiplied by the appropriate diversity factor. This procedure is to be applied to all pipe sections including those on branches.

c) It will be noted that the sum of the flows in all the branches will greatly exceed the design flow of the cold water pump. However, this is in order as each branch must be sized for its appropriate design flow.

d) The design should be refined to take into account any service which requires large quantities of water. The largest branch from the cold water system will be to the calorifiers and reconsideration of the pipe size may be required.

e) For each section of pipe a preliminary determination of the pipe size necessary to convey the required flow is to be made, taking into account the minimum pipe sizes for the number of washbasins and showers given in Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels. The maximum quantity which may be passed through each size of copper pipe is shown in Table 4. After assessing the balance of the initial sizing of the system it may be necessary to change the pipe size in some sections either to reduce or to increase the pressure drop. The values given are limiting values on the general levels to be followed. Higher speeds will be accepted for Submarine applications where space limitations may demand the fitting of smaller diameter pipework.

Table 4 - Domestic Fresh Water Systems, Pipe Size and Water Speeds

Pipe Maximum Mean Water Flow Size Bore

Weight of FW

(kg/m) Water Flow

(m3/h) Water Speed

(m/s) Friction Loss (m/100m run)

8 6.4 0.03 0.07 0.6 12.66 12 10.4 0.09 0.27 0.9 13.57 15 13.0 0.13 0.58 1.2 16.75 22 19.6 0.30 1.63 1.5 14.91 28 25.6 0.52 3.34 1.8 14.83 35 32.0 0.81 5.8 2.0 13.56 42 39.0 1.20 9.05 2.1 11.63 54 50.0 1.97 16.28 2.3 10.13

76.1 72.2 4.10 38.35 2.6 8.11 108 103.1 8.34 90.1 3.0 6.85 133 127.4 12.73 137.1 3.0 5.33

f) The proposed route of the pipe system is to be marked out on the ship deck plans and elevations and the following clearly indicated:

1) All bends and tee junctions;

2) All outlets and components to be served by the system;

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3) All valves, strainers, air releases, or other fittings to be inserted in the pipelines;

4) Pumps;

5) The design water flow for each section in m3/h;

6) The approximate lengths of all pipes in metre;

7) All junction points on the main and branch pipes. These are to be referenced using letters for junction to the main pipe, commencing with ‘A’ at the aft FW storage tank, and using numbers for branch pipe junctions. Each section of pipe will therefore be represented by the references of its extremities (e.g. A-B, A-1, etc).

NOTE When preparing the piping layout, the designer should also refer to the requirements for pipe installation given in clause 6.12.3.

g) The information from the ship plans may then be summarized in Annex C. on Data Sheets C2/1, C2/2, C2/3, C3/1, C3/2 and C3/3 and used to calculate the system pressure drop on Data Sheets C4/1, C4/2 and C4/3.

h) The FW system may usually be sized with acceptable accuracy using the ‘equivalent length’ method shown in Annex C. because the flows are variable and the pipe runs are not fully determined at the time of calculation.

i) Table 5 shows the ‘equivalent pipe length’ for various valves and fittings. Figure 6 gives a chart relating pipe size, pressure drop, water speed and flow quantity for the range used in cold FW systems. Figure 7 gives similar information for hot water systems.

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Table 5 - Equivalent Straight Pipe Length for Valves, Bends, Tees, etc.

Component Equivalent Pipe Length Coefficient (K) Valves: ball plug 15 ball plug (3–way) 60 Butterfly 30 Diaphragm 150 Gate 12 temperature control (3–way) 160 swing check 60 Strainers 40 Sudden change (large to small) 20 Bends: 90°R/D 8 12 45° 8 180°or 2 adjacent 90° 20 1 ↔ 2 Tees, dividing flow, ↓ 3 branch 1 → 3 Vb/V 0.5 250 Vb/V 1.0 70 Vb/V 1.25 60 Vb/V 1.5 50 Tees, dividing flow, main 1 → 2 Negligible 2 ↔ 3 Tees, Y dividing flow, ↓ 1 branch 1 → 2 or 1 → 3 Vb/V 0.5 250 Vb/V 0.7 120 Vb/V 1.0 70

Vb = branch velocity

V = combined flow velocity

Equivalent length = K x D1000

where K = Equivalent pipe length coefficient of component

D = pipe bore (mm)

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Figure 6 - Piping System Pressure Loss Chart (Fresh Water 10°C)

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Figure 7 - Piping System Pressure Loss Chart (Fresh Water 75°C)

j) The procedure described in clauses 6.11.2a) to 6.11.2i) inclusive is to be repeated for the hot water system.

k) The water usage in a ship is a function of the opportunities provided to use water as well as the size of complement. An approximate guide can be obtained from the size of pumps fitted to the types of ships as shown in Table 6, in relation to their complement. The selection of pump is somewhat narrow as the present approved range contains only two capacities of domestic cold water pumps, i.e. 10m3/h and 5m3/h.

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Table 6 - Example of Pump Fits

Ship Type Complement Number and Capacity Fitted Type 23 200 2 at 5m3/h Type 42/45 260/313 2 at 10m3/h Assault Ships 600 + 300 ‘Troops’ 4 at 10m3/h CVS 970/980 4 at 10m3/h CV(F) 1000 Total (Approx) 4 at 10m3/h

l) In ships of Frigate/Destroyer size and above, two pumps are normally to be provided for each group of storage tanks. In ships below Frigate/Destroyer size, one pump is to be provided for each group of storage tanks. At least two pumps are to be provided. The pumps are to be identical.

m) Very roughly it can be said that ships with a complement 250 and under will be fitted with two 5m3/h pumps. Ships with a complement 250 to 500 will be fitted with two 10m3/h pumps and ships with a complement over 500 will be fitted with four 10m3/h pumps.

6.11.3 Review of General Design

Because of the averaging and diversifying factors used in the initial and final design it is necessary for a general review to be made to ensure that these have not led the designer into design detail which is inappropriate to the duties of the system. A comparison with existing designs for similar ships which are known to be satisfactory or to have certain limitations would be advantageous.

6.11.4 Supplies to Washbasins and Showers

For arrangements and sizing of pipework in bathrooms see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels.

6.11.5 Diversity Factors for Outlets

a) Because of the large flow involved it is not feasible or desirable to design the system for all water outlets being in full use at one time.

b) The system is to be designed on the basis that the normal percentage of outlets that would be in use at any time will be as shown on Figure 8, ignoring outlets which are not in daily use, e.g. decontamination supplies, emergency supplies to sonar cooling equipment, etc. Figure 8 is basically intended for application to bathroom outlets but it is to be used, in the absence of more obvious ratios, for all multiple outlets.

c) The diversity factor as applied to any point in the system relates to the number of outlets downstream of that point. The diversity factor thus decreases as consideration moves from the branch extremities towards the pumps.

d) Certain outlets of a specialist nature may require a large water quantity at a specific pressure. The incorporation of such equipment in the system will necessitate modification of the method of calculating diversity factor.

e) For economic reasons, to obtain the limits of discharge for the various outlets the sizes that are to be fitted are shown in Table 7. The flow from showers given is to be taken as being provided 50% from the hot water system and 50% from the cold water system.

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Table 7 - Discharge Rate for Fittings

Fitting Size of Outlet (mm)

Flow Rate (m3/h)

Window washer 6 0.07 Washbasin/tap 10 0.27 Shower head 13 0.27 Tap 13 0.57 Tap 19 1.63 Tap 25 3.34

6.11.6 Cold Water Pump

a) The capacity of the cold water pumps are to be adequate to pass the diversified flow, ignoring outlets which are not in daily use.

b) The pressure developed is to be the system calculated pressure drop, Annex C. Data Sheet C4/3 plus 10% plus 0.35 bar. This pressure may need to be increased if there is a specific requirement for a pressure in excess of 0.35 bar for equipment at high level, e.g. bridge window washers 1.4 bar, see clause 6.3.1d).

c) The pump may now be selected, see clause 6.7.

d) The pump discharge pressure at zero flow from a full storage tank is to be obtained from the pump performance characteristic. This will be the maximum working pressure of the system.

e) In Submarines where the cold water system is pressurized by air and not by cold water pumps, the calculated pressure drop, Annex C. Data Sheet C4/3 plus 0.35 bar is to be the normal working pressure of the air in the FW storage tanks.

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Figure 8 - Diversity Factor: Number of Fittings Connected

6.11.7 Cold Water Boost Pump

a) Where the total static head exceeds 4 bar or 90% of the maximum head available from the cold FW pump selected, whichever is the lower, a boost system, supplied by a continuously running pump, is to be provided to serve the higher outlets. The limit of 4 bar has been selected to prevent lower outlets from being subjected to unduly high pressures. The limit of 90% of the maximum head available from the cold FW pump provides a 10% margin between head available and required to allow for any errors in calculation.

35

Def Stan 02-728 Issue 3 b) The most convenient point to install the boost pump is to be selected, so as to be close to the

maximum demand on the boost circuit and to suit the ship’s arrangement. Note that the bridge window washers are likely to be on this circuit. The point selected is to serve all outlets on the top decks and is to be suitable for use with either cold water pump operating. The most suitable point will probably be in the main branch to the top decks. If more than one branch is proposed, consideration is to be given to re–arranging the piping to provide one main branch to the top deck, to installing more than one boost system or to providing a main feed from boost pumps at each end.

c) When it is decided that a cold water boost pump is to be installed then the differential head necessary from the cold water pump is to be re–assessed to allow for the lower static lift required.

d) The minimum differential head necessary from the boost pump is to be determined by adding 0.35 bar to the maximum total head loss for the section supplied by the boost pump.

6.11.8 Pressure at Outlets

a) Once the pump pressure is known, the minimum pressure expected at all outlets under design flow conditions is to be established in turn. As a general rule, where the pressure at an outlet is in excess of a gauge pressure of 2 bar in the cold and hot water systems, consideration is to be given to reducing the pressure first by re–calculating for smaller pipes. Use of smaller pipes means saving in weight, cost and size of fittings as well as piping. Several re–calculations for pipe size may be advantageous, subject to the limitations that the general water velocities do not exceed those given in Table 4 and that the minimum pipe bore is not less than 13mm diameter in the main system or main branches. In Submarines higher speeds will be accepted where space limitation demands the fitting of smaller bore pipework. It will be noted that application of the pipe sizes given in Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels for washbasins and showers automatically keeps the water speeds in these areas below the limiting speeds given in Table 4.

b) If it is not possible to reduce the pressure by the above method, orifice plates of brass or nylon are to be fitted to the connections to all washbasin taps and shower head fittings, etc, to limit the outlet pressure to 2 bar and the flow rates to the quantities given in Table 7. Fitting the orifice plate to the connections (see Figure 9) makes the orifice plate peculiar to the system and permits a standard tap or shower head to be fitted. The size of orifice plate installed is to be selected from the preferred range shown in Table 8.

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Figure 9 - Washbasin Taps and Shower Head Fittings - Fitting of Orifice Plates

Table 8 - Range of Orifice Plates

Pressure in Main (bar) Size of Orifice (mm) over 3 2.5 2 to 3 3.0

6.11.9 Hot Water Circulation

a) Hot water is to be circulated round the ring main so as to ensure that the temperature drop at any branch does not exceed about 5°C during periods of low demand.

b) It is possible to maintain adequate circulation by natural thermo–siphon action when the system resistance is low in relation to the vertical height of the flow and return legs. Table 9 may be used to determine if natural thermo–siphon is possible.

c) For compact systems on one deck, serving for example the galley and dependencies or a group of washplaces, it may be possible to omit the use of a circulating pump if the draw–off is reasonable when the system is used after a period of no demand. Otherwise, a hot water circulating pump is to be fitted to maintain the ring main at the required temperature and pressure.

d) The pump selected may be capable of circulating flows in excess of the calculated circulation. Therefore, a check is to be made to ensure that the electric motor supplied with the circulating pump will not be overloaded when the pump runs out on its characteristic.

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Table 9 - Conditions for Thermo–Siphon

Pipe Size of Ring Main (mm)

Maximum Equivalent Length of Ring Main For Each 1 m Vertical Lift of Hot and Cold Legs (including allowance for

Valves, bends, etc) (m) 28 20 35 25 42 30 54 45

6.11.10 Selection of Calorifier

a) Consideration is to be given to the type of energy to be supplied to the calorifiers, as to whether it should be electric or steam or duplicated by both or a mixture of both. The decision will depend largely upon the design of the auxiliary energy equipment on the ship but in addition the following points need to be considered:

1) A steam control system can be modulated smoothly whereas electrically heated calorifiers impose step load changes on the power supply.

2) The hot water temperature in a steam calorifier will be more smoothly maintained than that in electrically heated units in which a ‘cut–in’ and ‘cut–out’ hysteresis is associated with the dividing of the heating duty into convenient steps.

3) On steam heated calorifiers the full load heating capacity may be uncertain by design and by installation reasons because of lack of ‘type testing’ of some particular designs and because the steam pressure at the calorifier is often significantly below the calorifier design steam pressure. With electrically heated calorifiers the maximum available heat is definite.

b) The total number of calorifiers installed in the ship are to have a capacity of 0.77 kW per person of complement. This is equivalent to a hot water flow of 0.012m3/hour for each person with the water temperature raised from 10°C to 65°C.

c) For steam heated calorifiers provided that the total output of the calorifier to the water is specified, the manufacturer will arrange for the heat input to cover the surface heat emission. It is necessary to allow for the surface losses from electrically heated calorifiers and the piping system. However, these losses are small and unless the calorifier rating is close to the required rating the losses can be ignored. Table 10 gives the loss per metre run of normally insulated pipe for use when it is decided to calculate the heat losses.

Table 10 - Hot Water Piping Heat Emission and Temperature Drop

Pipe Size (mm)

Rate of Heat Emission (W/m run)

Initial Rate of Temperature Drop (°C/h)

15 7.1 45.3 22 8.9 25.0 28 10.4 17.2 35 12.2 12.9 42 13.9 9.9 54 16.8 7.2

d) The values given show the rate of heat release and of drop of temperature of water at 77°C in pipes insulated with 19mm rigid plastic foam (Thermal conductivity 2.3 x 10 5 kW/m°C) in an ambient of 15°C and minimal flow rate.

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6.11.11 Hot Water System Peak Load

When the heating capacity of calorifiers is sized on the basis given in clause 6.11.10b), ‘peak’ demands on the system in excess of this requirement will arise. It will not be possible to cater for every ‘peak’ heat load which can arise on the hot water system. The ‘peak’ demands for hot water are to be catered for by storage capacity which is normally to be combined with the calorifier units. Such ‘peaks’ of hot water are caused by the maximum usage of bathrooms when all ship’s complement want to wash/shower at the same time.

6.11.12 Hot Water Storage Capacity

a) The storage capacity required is to be sufficient to ensure that the ‘peak’ demand described in clause 6.11.11 can be met over a period of 60 minutes without the water temperature falling from an initial 65°C to below 50°C.

b) The minimum capacity is to be 0.114m3 for small bathrooms or groups of fittings, the maximum capacity being 0.455m3.

c) When sizing a calorifier for a particular duty the capacity should be determined after discussion with the supplier and investigation of the space available. For systems where the duration and magnitude of the peak hot water load is known the required storage capacity can be estimated by interpolation from Figure 10 to Figure 14 inclusive. These curves show the variation of hot water outlet temperature with time in various conditions and are based upon the following controlling factors:

1) Heat input maximum (kW) = 20, 50, 100, 250, 300, 350 and 400;

2) System pipe capacity is 0.136m3;

3) Calorifiers storage capacity (m3) = 0.023, 0.27, 0.45, 0.91;

4) Cold water is supplied at 10°C;

5) Initial water temperature in the calorifier is 65°C;

6) Circulation around the system is at 1.36m3/h;

7) Hot water outlet rate (m3/h) = 0.23, 0.45, 0.91, 1.36, 1.82, 2.73, 3.41, 3.63, 4.55, 6.82, 9.1.

d) To produce curves for all of the above combinations of heat input, water outlet rate and storage capacity would result in an excessive number of graphs. The curves plotted were, therefore, kept to a minimum but the curves selected are sufficient to ensure that an adequate comparison can be made for other combinations of heat input, water outlet and storage capacity considered but for which curves have not been produced. To achieve this, graphs were produced with a selection of curves where the water temperature is maintained above 60°C throughout plus a selection where the water temperature drops below 60°C within 60 minutes. From these curves it can be determined for other combinations of heat input, water outlet rate and storage capacity whether or not a water temperature of 60°C is maintained after 60 minutes.

e) The curves are arranged as follows:

1) Figure 10 - This indicates the hot water temperature against time for a storage capacity of 0.023m3 and enables interpolation to be made for combinations of head input from 20kW to 100kW and water outlet rate from 0.23m3/h to 1.36m3/h.

2) Figure 11 - This indicates the hot water temperature against time for a storage capacity of 0.27m3 and enables interpolation to be made for combinations of head input from 20kW to 100kW and water outlet rate from 0.23m3/h to 1.36m3/h.

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3) Figure 12 - This indicates the hot water temperature against time for a storage capacity of 0.455m3 and enables interpolation to be made for combinations of heat input from 20kW to 400kW and water outlet rate from 0.23m3/h to 0.1m3/h.

4) Figure 13 - This indicates the hot water temperature against time for a storage capacity of 0.91m and enables interpolation to be made for combinations of heat input from 250kW to 400kW and water outlet rate from 3.41m3/h to 9.1m3/h.

5) Figure 14 - This indicates the effect of changing the storage capacity. To provide similar information for all heat inputs and hot water outlets would necessitate a large number of curves. Figure 14 has therefore been drawn for a heater input of 100kW and a water outlet of 0.91m3/h merely to illustrate the value of changing the storage capacity.

NOTE It should be recognized that the capacity of the cold water pump may also be a limiting factor should a peak hot water demand coincide with a general peak demand. In these circumstances certain limitations may have to be tolerated.

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Figure 10 - Hot Water Temperature from Calorifier: Time for a Storage Capacity of 0.023m3

41



42



43



44


Figure 14 - Hot Water Temperature: Time Effect of Change in Storage Capacity

45

Def Stan 02-728 Issue 3 6.11.13 Electric Water Heaters

Isolated positions which cannot conveniently be served by the hot water system are to be supplied by individual electric water heaters. Individual electric water heaters are also required in medical compartments for emergency use (see clause 6.8.3b)).

6.11.14 Accumulator for Thermal Expansion

a) The accumulator is to be designed to absorb, without significant increase in system pressure, the increase in volume when the water in the hot water ring main is heated between an arbitrarily chosen 54°C and the thermostatically controlled limit of 70°C during zero discharge. (See Def Stan 02-329).

b) An increase from say 10°C to 70°C will arise very infrequently and would be associated with an excessively large accumulator. This condition will not be catered for by the accumulator but will be left to the calorifier relief valve.

c) The volume of water contained in the hot water ring main is to be assessed and added to the known storage capacity of the calorifier. The increase in volume due to this total volume expanding thermally from 54°C to 70°C is to be calculated. This is the volume to be absorbed by the accumulator.

d) Table 4 gives the weight of water in 1m length of pipes of various bores used in hot water systems.

e) The accumulator separator bag is to be pre–charged with air to a pressure (P1) equal to the maximum zero flow discharge pressure of the cold water pump (ie the hot water system maximum working pressure). In absorbing the increase in volume the pressure in the accumulator is to be allowed to rise by 1.4 bar. The upper pressure (P2) therefore equals P1 + 1.4 bar. The 1.4 bar increase is specified on the basis that the calorifier relief valve is specified to commence to lift at this point.

f) The required capacity of the accumulator is to be approximately 5% of the total hot water system capacity, including calorifier.

6.11.15 Provision for Air Removal

a) For the satisfactory operation of the FW systems provision must be made for the removal of air in the system which collects at high points, either because it had been in the water of the system or because it was not cleared out of the system during the initial fill.

b) FW systems are to be provided with the following:

1) Air bleed positions at every high point of the system. Each of these is to consist of a pipe boss to which is fitted either an air bleed cock, or a length of piping with the bleed cock at its end in an accessible position;

2) A number of air collecting vessels, in addition to the requirements of 1) above. These operate by reducing locally the water velocity to one–quarter of its normal value, which permits air closely mixed with the water or in solution to separate and collect at the top of the vessel, from which point it may be drawn off.

c) Air collecting vessels should be fitted in horizontal pipes of the largest convenient size, subject, for space reasons to a maximum of 54mm pipe size. They may be fitted in either flow or return pipes, as convenient.

d) Figure 15 shows a typical air collecting vessel arrangement. Requirements for automatic air release units are given in clause 6.10.4.

46


Figure 15 - Typical Air Collecting Vessel

e) Figure 16 and Figure 17 show the arrangements for installing air collecting vessels with manual and automatic air release.

Figure 16 - Air Collecting Vessel and Manual Air Release

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Figure 17 - Air Collecting Vessel and Automatic Air Release

6.12 Installation and Testing

6.12.1 General

a) Meticulous attention to the standard of workmanship, finish, cleanliness and inspection throughout construction is necessary.

b) Flexibility is to be built into the systems to absorb the movement of the hull in normal and heavy sea conditions and to cater for possible changes in temperature of the hot water system.

6.12.2 Fresh Water Storage Tanks

a) Design requirements for FW tanks are given in clause 6.6.2.1.

b) Butt welds in tank boundary plating which forms part of the ship's side or is adjacent to other tanks which contain, or may contain, fuel oil or SW are to be full penetration welds and are to be subjected to 100% radiographic examination. Fillet welds at such tank boundaries are to be 100% inspected by magnetic crack detection.

c) Welds in tank boundaries not included in clause 6.12.2b) are to be radiographed to the same extent as the hull structure.

6.12.3 Piping Installation

a) Piping is to be arranged in a neat and orderly manner, and as short as possible consistent with the design requirements for access, flexibility and ease of maintenance. Wherever possible flanges and fittings in parallel systems are to be staggered.

b) Piping is to permit free passage in the walkways and working spaces and permit maintenance of the ship’s structure.

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c) Piping is to be arranged to allow for the full thickness of the thermal insulation as required by Def Stan

02-703.

d) Straight lengths of piping between bulkheads, decks or anchor points are to be avoided.

e) All piping is to be readily accessible throughout its length and arranged not to restrict headroom and as follows:

1) Clear of bulkhead stiffeners, deck beams and plating butts and seams to allow for shock movement and maintenance;

2) Clear of the underside of hatch openings to avoid being used for handholds;

3) Not to encroach on equipment removal routes, see Def Stan 02-302 Part 1 (for legacy fits) for Surface Ships and Def Stan 08-103 Part 2 (for legacy fits) for Submarines.

f) Deck and bulkhead pieces, conforming to BR 3013(2), are to be fitted where pipes pass through watertight structures. Any flange connection necessary to the structure is to be entirely independent of the pipe joint. Jointing flanges of pipes passing through decks are to be so arranged that they are at least 150mm clear of the deck.

g) Joints are to be positioned to facilitate access, removal of machinery and equipment.

h) Joints are to be arranged so that any leakage will not damage equipment or constitute a hazard or endanger personnel.

i) Where practicable, piping layouts are to be designed to permit shop fabrication. In such designs an adequate number of closing lengths are to be incorporated. Closing lengths are to be made to a template.

j) Where a pipe is to be connected to a valve or fitting, a suitable connection or ring flange (see clause 6.10.3.1) is to be fitted to the pipe to interface with the valve or fitting.

k) Straight piping of at least six diameters in length is to be provided downstream of all turbulent raising equipments, e.g. throttling valves, bends, tees, etc.

l) Where high and low points are unavoidable, vents and drains are to be provided.

m) Wherever practicable, pipes are not to pass through electrical spaces such as distribution centres or compartments containing switchboards, electronic cubicles and other large non–watertight electrical equipment. When this is not possible the piping is to have no joints or valves within the compartment. Should it be essential to have a valve or joint in the compartment, agreement must be obtained as to the acceptable arrangement and siting of deflectors, shields and/or drip trays necessary to protect the equipment from leaks and/or sprays.

n) Pipes are to be cased in where required and adequately stayed.

o) The design of the pipe supports is to be in accordance with BR 3021(2). The number of supports is to prevent excessive vibration but should not restrain the pipes so as to cause excessive transfer of load from the structure to the pipe.

p) Where pipes are attached to structure likely to be affected by gun-blast, the pipe hangers are to be closely spaced and well secured on structural members i.e. deck beams or girders, not on deck panels.

q) Supports are to be installed for fittings and heavy valves to prevent their weight being supported by the attached piping.

49

Def Stan 02-728 Issue 3 r) Adequate clearance is to be provided to allow for designed deflection of system components under

shock. Due account should be taken of the deflection of the supporting structure and other equipment under the shock load.

s) Pipework adjoining flexible assemblies is to be supported as close as possible to the flexible pipe. The supports are to be installed to prevent such misalignment of the flexible assembly as to cause the transmission of excessive forces to the connected machinery.

t) In piping systems the straight portion is to be worked as far as possible in standard lengths, convenient for dismantling.

u) Bends in pipes are to conform to the requirements of clause 6.12.6. Short stiff bends are to be avoided, particularly in positions likely to be subjected to vibration.

v) Copper pipes are to be kept clear of aluminium alloy structure. At least a 12mm gap is to be left between the pipes or the pipe insulating material and the structure.

w) Non–ferrous piping is not to be fitted into any part of the ship so low as to come into contact with bilge water.

6.12.4 Welding

The requirements of the documents listed in Table 11 are to be followed to cover specialized application of welding. The requirements of these documents are mandatory.

Table 11 - Welding Requirements

Document Requirements Covered

Def Stan 02-706 Welding and fabrication of ships’ structures

Def Stan 02-729 Pts 1 to 5 Non–destructive examination procedures

Def Stan 02-772 Welding

Def Stan 02-745 Classification, inspection requirements and acceptance standards for steel castings

Def Stan 02-769 Welding consumables for structural steel

Def Stan 02-771 Repair welding of copper–based alloy castings

Def Stan 02-773 Minimum acceptance standards for welded joints

6.12.5 Brazing

Brazing is to conform to the requirements of Def Stan 02-743 Part 5.

6.12.6 Pipe Manipulation

a) The procedures and acceptance standard for bending of metallic pipes are to conform to the requirements of Def Stan 02-743, Part 1.

b) Bends in pipes are to be the largest practical radius and at least 3D to the centre line of the pipe. In cases of extreme limitations pre–formed elbows of 2D radius or cast gunmetal bends as specified in BR 3013(2) will be permitted. On Submarines the minimum radius may be reduced to 2D, 1D bends may be used in certain circumstances and the specific approval of DPA is to be sought where their use is intended.

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6.12.7 Castings

a) Castings are to conform to the requirements of Def Stan 02-745.

b) Any check valves used in association with valves on the ship’s hull are to be to the same classification requirements that apply to the hull valves. Exceptionally on Submarines where the hull valve has a non–return facility this classification will not apply to check valves. To differentiate between hull valves and other valves of identical design, the valves for use on the hull are to be marked HULL ONLY in a low stress area.

6.12.8 Cleaning and Preservation

6.12.8.1 General

a) Requirements for cleaning and preservation are to conform to Def Stan 02-341 Part 1 and Warpaint.

b) Red and white lead is not to be used in FW systems.

6.12.8.2 Fresh Water Storage Tanks

a) Internal surfaces of steel FW tanks are to be treated in accordance with the requirements of Warpaint.

b) On completion of the coating of the inside of the tanks, they are to be sealed and no re-entered until the requirements of clause 6.12.11 are undertaken.

6.12.8.3 Tubes and Pipes

Copper tubes and pipes are to be cleaned and preserved after bending, brazing or welding on flanges and couplings, flange facing and drilling in compliance with the requirements of Def Stan 02-341 Part 1.

6.12.9 Fresh Water Tank Calibration

a) The FW tanks are to be calibrated in tonne either by filling with a known quantity of water or by calculation. The required method will be stated in the STR.

b) The results are to be tabulated and the capacity curves, showing the capacity in tonne against depth, forwarded to DE&S PIPT.

c) Calibration index plates of nickel silver are to be supplied and fitted at each sounding position except where clause 6.6.3.2f) applies. The following information is to be engraved on each plate:

1) Contents of the tank in tonne and decimals of a tonne corresponding to the soundings in metres and millimetres;

2) The distance of the water surface below the top of the sounding tube when the tank is 95% full, to be engraved in red.

6.12.10 Pressure Tests

6.12.10.1 Tanks

a) In HM Surface Ships tanks are to be tested to the pressure given in Def Stan 02-155 Part 1 (for legacy fits) for a period of 72 hours.

b) In Submarines the tanks are to be tested in accordance with the requirements of the STR.

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Def Stan 02-728 Issue 3 c) The pressure to which the systems are to be designed is the shut valve pressure of the pumps, i.e. the

maximum working pressure.

d) The various parts of each installation are to be tested during manufacture to two times the maximum working pressure and after installation onboard to one and a half times maximum working pressure.

e) The DE&S PIPT Quality Assurance Representative (QAR) is to be informed when pressure tests will be carried out during manufacture so that representation can be arranged if required. Similarly, the DE&S PIPT QAR is to be notified when all pressure tests are carried out on board.

f) Clean FW is to be used for all tests during manufacture and after installation onboard.

g) Test pressures are to be maintained for periods decided by the Inspecting Authority as adequate to permit a thorough and complete inspection of all parts for leaks. Test pressures are to be maintained for at least 30 minutes.

h) Shop pressure tests are to be carried out after all welding or brazing and machining has been completed with all holes for securing the insulation drilled and before paint, insulation or covering of any kind has been applied. The tests after installation may be carried out with insulation in place, but the joints of pipe flanges, connections and valves are to be uncovered.

i) Any equipment that may be opened up after the manufacturer’s shop tests must be re–tested to shop or installation test pressure as appropriate to show that it functions correctly after re–assembly.

j) Parts tested are to be clearly stamped or etched or, where special materials are involved, painted by the manufacturer with his identification mark, the test pressure and the date of the test.

6.12.10.2 Valves

a) All valve bodies are to be tested to twice the working pressure. After assembly all valves are to be tested to the working pressure with the valve half open to test the gland. All except ball valves are then to be tested closed with one and a half times working pressure on the inlet side of the valve. Valves which may admit pressure from either side in service, except ball valves, are to have the test pressure applied independently on each side. Ball valve seats are to be tested to working pressure only for freedom from seat leakage as the design of these valves is such that an increase in pressure ensures a tighter seal and therefore the lower pressure is more critical.

b) For ball and butterfly valves, directly on completion of the tests above, at least one in five of production batch is to be air bubble tested from 0.35 bar to 0.7 bar on each seat independently; no leakage is to occur.

c) All valves are to be suitable for a working pressure of 12 bar and the test pressure is to be based on this figure irrespective of the working pressure of the system.

6.12.10.3 Pipework in Submarines

In addition to the requirements of clause 6.12.10, any section of piping inside the containment boundary may require to be tested to the containment pressure, depending on the system arrangement and the requirements in the STR.

6.12.11 Trials

Trials are to be carried out to demonstrate the correct functioning of the made and FW systems in accordance with Lloyd's Register "Rules and Regulations for classification of Naval Ships" Volume 2, Part 11, Chapter 1. A minimum pressure of 0.35 bar is to be available at the outlet most remote from the pumps when the system is operating at full load. Additionally, a pressure of 1.4 bar is to be available at the Bridge Window Washer Systems.

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6.12.12 Inspection and Flushing

The final cleaning of the FW storage tanks is to be carried out by personnel of clean habits wearing clean overalls and rubber shoes. The inspection of the systems and tank coatings is to be carried out by the Shipbuilder and DE&S PIPT prior to the initial filling and flushing of the system. When the system is pronounced clean of all swarf, etc, the tanks, filling system, circulating system and distilling system are to be filled with superchlorinated FW, as per BRd 820 Chapter 4. Thereafter, the systems are to be completely drained and then refilled with clean fresh water, there being sufficient chlorine remaining in the system to make this final filling an acceptable potable water.

6.12.13 Insulation

a) Thermal insulation, conforming to Def Stan 02-703 is to be applied to cold FW piping where it passes through store rooms and accommodation spaces, over electrical equipment and in any other location where condensation is unacceptable. Hot FW piping is to be insulated with the exception of that stated in clause 6.12.13b).

b) All FW piping on the surface of the lining in cabins, washplaces and showers is not to be insulated. In Submarines, piping behind linings is not to be insulated.

6.12.14 Colours and Marking

a) FW piping systems are to be identified with pressure sensitive identification tapes conforming to Def Stan 02-853 Part 1 for HM Surface Ships and Def Stan 02-853 Part 2 for Submarines.

b) All pipes of 25mm OD and above (including insulation, if fitted) are to be identified by stencilled system code letters as follows:

1) Cold FW system FWC

2) Domestic Hot FW FWH

c) All pipes of less than 25mm OD (including insulation, if fitted) are to be identified by colour banding. The pipe coupling is to be painted Middle Brunswick Green (BS 381C colour No 226). The length of pipe 150mm each side of this coupling is to be painted Azure Blue (BS 381C colour No 104). Valve levers are to be painted Azure Blue. Where there are no pipe couplings 50mm of piping is to be painted to represent the coupling and 150mm each side of this band is to be painted with pipe colouring.

d) The colour banding of pipes is to be kept to a minimum, being used only for lengths of pipes which cannot be easily identified by other means, e.g. valve levers or near attachments to readily identifiable machines or equipment.

e) Entry points to potable water tanks are to be clearly labelled "Potable Water".

53


Annex A Normative References

A.1 Reference Information

A.1.1 The publications shown below are referred to in the text of this standard. Publications are grouped and listed in alpha-numeric order.

BRd 820 Potable Water Management

BR 1333 Desalination Plant Manual

BR 2170 CBRNDC Manual Vol 1 Damage Control Vol 2 NBS Defence Vol 3 NBCD Stores Catalogue for HM Surface Ships and RFS'a Vol 4 Submarines Vol 5 CBRNDC Advancement and Training Requirements Vol 6 CBRNDC Incidents

BR 3013(2) Admiralty Pipework Standards (Metric)

BR 3021(2) Shock Manual (Metric)

BS 381C Specification for Colours for Identification, Coding and Special Purposes

BS 1553-1 Specification for Graphical Symbols for General Engineering Part 1 Piping Systems and Plant

BS 3692 ISO Metric Precision Hexagon Bolts, Screws and Nuts

BS 5070-3 Engineering Diagram Drawing Practice Part 3 Recommendations for Mechanical/Fluid Flow Diagrams

BS 7371-12 Coatings on Metal Fasteners. Requirements for Imperial Fasteners

BS EN 1057 Copper and Copper Alloys. Seamless, Round Copper Tubes for Water and Gas in Sanitary and Heating Applications

BS EN 1254 Copper and Copper Alloys. Plumbing Fittings Part 1 Fittings with ends for Capillary Soldering or Capillary Brazing to Copper Tubes Part 2 Fittings with Compression Ends for use with Copper Tubes

BS EN 10028 Flat Products Made of Steel for Pressure Purposes: Part 1 General Requirements Part 2 Non–alloy and Alloy Steels with Specified Elevated Temperature Properties Part 4 Nickel Alloy Steels with Specified Low Temperature Properties

BS EN 10029 Specification for tolerances on Dimensions, Shape and Mass for Hot Rolled Steel Plates 3mm Thick or Above

54

BS EN 10216-2 Seamless Steel Tubes for Pressure Purposes. Technical Delivery Conditions. Part 2 Non-Alloy and Alloy Steel Tubes with Specified Elevated Temperature Properties


BS EN 10217-2 Welded Steel Tubes for Pressure Purposes. Technical Delivery Conditions. Part 2 Electric Welded Non-Alloy and Alloy Steel Tubes with Specified

Elevated Temperature Properties

BS EN 10255 Non-Alloy Steel Tubes suitable for welding and threading, Technical delivery conditions

BS EN ISO 1461 Hot Dip Galvanized Coatings on Fabricated Iron and Steel Articles. Specifications and Test Methods

BS EN ISO 2081 Metallic and Other Inorganic Coatings. Electroplated Coatings of Zinc with Supplementary Treatments on Iron or Steel

Def Stan 02-101 Requirements for Design and Fitting Out of Workshops Maintenance Spaces and Engineering Stores for HM Surface Ships (Cat 2): Part 1 Common Requirements Part 2 Specific Requirements

Def Stan 02-102 Requirements for Air Conditioning and Ventilation Design (Cat 2): Part 1 HM Surface Ships and Royal Fleet Auxiliaries

Def Stan 02-106 Requirements for Medical & Dental Organization in HM Surface Ships and Submarines Part 1 Common Requirements – Medical and Dental Facilities Part 2 Specific Requirements – Medical and Dental Facilities in HM Ships Part 3 Specific Requirements – Medical Organization for Action in HM Surface Ships Part 4 Medical and Dental Facilities in Submarines

Def Stan 02-112 Requirements for Windows and Window Wipers for HM Surface Ships (Cat 3)

Def Stan 02-120 Requirements for WC, Urinals, Bathrooms and Washing Facilities in HM Surface Ships and Submarines (Cat 2) (Obsolescent)

Def Stan 02-121 Requirements for Galley & Associated Spaces Part 1 Common Requirements Part 2 Specific Requirements – Surface Ships Part 4 Specific Requirements – Nuclear Submarines

Def Stan 02-123 Requirements for Laundries and Associated Compartments (Cat 2): Part 1 Laundries and Associated Compartments Part 2 Laundry Machinery, Equipment and Fittings

Def Stan 02-155 Requirements for Structural Practices in Steel Surface Ships Part 1 General Requirements (Obsolescent)

Def Stan 02-302 Requirements for Maintenance Envelopes and Removal Routes Part 1 Surface Ships (Obsolescent)

Def Stan 02-309 Requirements for Gas Turbines (Cat 2)

Def Stan 02-327 Requirements and Guidance for the Procurement of Pumps for Auxiliary Systems (Cat 2)

Def Stan 02-329 Requirements for Heat Exchangers for HM Surface Ships and Submarines (Cat 2)

55

Def Stan 02-728 Issue 3 Def Stan 02-341 Requirements for Cleaning of Items, Components and Equipment for Fluid

Systems (Cat 2) Part 1 Cleaning

Def Stan 02-360 Guidance to the Selection of Low Pressure Metric Standard Valves (Cat 3)

Def Stan 02-703 Thermal and Acoustic Insulation of Hull and Machinery (Cat 2)

Def Stan 02-706 Welding and Fabrication of Ships’ Structure (Cat 2)

Def Stan 02-710 Fluid Systems General Requirements (Obsolescent)

Def Stan 02-729 Requirements for Non–Destructive Examination Methods (Cat 2): Part 1 Radiographic Part 2 Magnetic Particle Part 3 Eddy Current Part 4 Liquid Penetrant Part 5 Ultrasonic

Def Stan 02-743 Pipe Manipulation (Cat 2): Part 1 Bending Pipes Part 5 Brazing

Def Stan 02-745 Classification, Inspection Requirements and Acceptance Standards for Steel Castings

Def Stan 02-748 Strainers, Preferred Range (Cat 3)

Def Stan 02-769 Approval Systems for Welding Consumables for Structural Steels

Def Stan 02-771 Requirements, Procedure and Inspection for Weld Repair of Copper Alloy and Nickel Alloy Castings

Def Stan 02-772 Welding of Ferrous and Non Ferrous Metallic Materials

Def Stan 02-773 Minimum acceptance standards for welds in HM surface ships and submarines (Cat 1)

Def Stan 02-797 Pipe work Engineering (Cat 2): Part 1 General Part 4 Screwed Fittings

Def Stan 02-830 Requirements for Gunmetal Ingots and Castings (Cat 3) Part 1 Gunmetal Ingots and Class III Gunmetal Castings

Def Stan 02-833 Requirements for Nickel Aluminium Bronze (Cat 2) Part 2 Forgings, Forging Stock, Rods and Sections

Def Stan 02-837 Requirements for Copper Tubes (Cat 3)

Def Stan 02-853 Requirements for the Identification, Colours and Markings for Systems (Cat 2) Part 1 Surface Ships Part 2 Submarines

Def Stan 05-10 Product Definition Information Part 0 General Introduction to Product Definition Information Part 1 Hardcopy/Microform Product Definition Information Part 2 Digital Product Definition Information Part 3 Product Definition Information Guidance

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Def Stan 07-204 The Requirements for Fire Protection and Damage Control for HM Surface

Ships (Cat 2)(Restricted Commercial) Part 1 Policy for Surface Ships

Def Stan 08-103 Requirements for Maintenance Envelopes and Removal Routes Part 2 Requirements for Submarines (Obsolescent)

Def Stan 08-133 Requirements and Guidance for the Aviation Arrangements in Surface Ships (Cat 1) Part 1 Guidance for the Completion of Aviation Requirements Part 2 Guidance for the Design and Construction of Aviation Requirements

Def Stan 08-144 Material Requirements for the NBC Defence of HM Surface Ships including RFA (Cat 1)

Def Stan 08-159 Requirements for Air Conditioning and Ventilation Design (Cat 2) Part 2 Submarines

Def Stan 08-204 Requirements for Damage Control and Fire Protection for the Safety Of HM Surface Ships and Submarines Part 3 HM Surface Ships and Submarine Equipment

JSP430 Ship Safety Management System Handbook: Volume 1 Policy and Guidance on MoD Ship and Equipment Safety Management

MAP 01-107 Design Guidance for Surface Ship and Submarine Accommodation Part 1 Process Guide Part 2 Technical Annexes

Warpaint Approved Paint Coatings for In Service and New Build Royal Navy Vessels

The following drawings are referred to in this Def Stan:

SDN 003 503 642 Sounding Tube, Flush Deck and Raised Fittings

SDN 003 503 703 Sounding Tube, Raised, General Arrangement

SDN 000 819 097/1-2 Fresh Water Filling Breaching Piece

SDN 000 819 098/1-3 Fresh Water RAS Deck Connections and Adaptors

A.1.2 Reference in this Standard to any normative references means in any Invitation to Tender or contract the edition and all amendments current at the date of such tender or contract unless a specific edition is indicated.

A.1.3 In consideration of clause A.1.2 above, users shall be fully aware of the issue and amendment status of all normative references, particularly when forming part of an Invitation to Tender or contract. Responsibility for the correct application of standards rests with users.

A.1.4 DStan can advise regarding where normative references documents are obtained from. Requests for such information can be made to the DStan Helpdesk. How to contact the helpdesk is shown on the outside rear cover of Def Stans.

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Annex B Definitions

B.1 Definitions

B.1.1 For the purposes of this Def Stan the following definitions apply:

Accumulator A vessel designed to absorb, without sufficient change in the system pressure to cause the relief valve to lift, the change in volume when the hot water system temperature rises during a lull in usage after a period of heavy demand.

Air Release Valve A valve designed to automatically pass to atmosphere the air accumulated in a collecting vessel sited in a low pressure, high temperature region.

Ball Valve A form of shut-off device having a ball which can be turned to move its port or ports relative to the body section ports to control or direct the flow of fluid.

Bibcock A draw-off cock with a disc screwed down against water pressure on to a horizontal inlet and fee outlet.

Calorifier A pressure vessel for heating and storing water for domestic use. Calorifiers may be supplied with energy by electricity, steam or waste heat.

Cock A form of shut-off device comprising a body having a parallel or taper seat into which is fitted a plug which can be turned to move its port or ports relative to the body ports to control the flow of fluid.

Cross connection A cross connection, in potable water terms, is the contamination of water supplies through either the interface of users with water systems, or through the interface with other water systems, e.g. waste, seawater or fire main.

Frost Plug A plug fitted to fresh water pipes in exposed positions to permit draining of the pipe when the vessel is in arctic or sub-arctic conditions.

Head The pressure of a fluid or the components of that pressure may be expressed as the equivalent fluid head, defined as the height of a column of fluid that would exert the fluid pressure at its base.

Head Losses The losses in head as a result of fluid flow and changes in fluid height: Friction Losses Dynamic Losses Loss due to changes in head above datum

Leak-off for Pumps The passage of the minimum flow of water from a pump discharge to the storage tank, usually controlled by an orifice, to prevent overheating of the pump at times of no flow.

Maintenance Envelope The minimum space required around an equipment for operation, maintenance and removal activities.

Net Positive Suction Head (NPSH) The head of fluid the pump requires above the vapour pressure to provide the energy necessary to force the fluid into the impeller vanes so that there is no significant loss in pumping efficiency due to cavitation.

58


NPSH Available The absolute static head of fluid available at the pump inlet minus the vapour

pressure. In practice the system designer will inform the pump manufacturer of the NPSH available at the pump suction flange; the pump suction flange is taken as the pump inlet.

Pipe Size The pipe outside diameter as stated in BR 3013(2) Part 2

Project Aquatrine Project AQUATRINE has transferred the responsibility for the maintenance and operation of the department's water and wastewater assets and infrastructure throughout Great Britain to private sector providers. This has involved leasing the assets to the service providers for the duration of the 25-year service period. The project covers the MOD's water processing plants and water mains, sewage work, sewers and drains that are outside buildings, removal of surface water and water supply for fire fighting use.

Push Cock, Non-concussive A bibcock type of valve arranged so that it is opened by pushing against a spring and incorporating a device to eliminate the production of water hammer on closure.

Strainer A device used to remove solid contaminates from a fluid by means of a perforated element in which the individual apertures, usually of a simple geometric form, permit the passage of a fluid in straight lines.

Thermo-syphon The natural circulation of water round a closed system caused by the temperature in one vertical leg being greater than in the other vertical leg.

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Annex C Sample Calculations and Formula

C.1 Introduction

a) The sample calculation is based on a typical fresh water system for a Frigate/Destroyer. The sample calculation is in SI units using metric pipe sizes.

b) Whilst it is necessary to carry out an analysis of the entire cold and hot water systems in order to determine the pressures at the various points and the maximum required pressure from the cold water pumps, for simplicity these sample calculations have been abbreviated to show only the major steps. Estimated values are shown for the omitted steps. Such estimated values are indicated with an asterisk.

c) Similarly for the calorifiers, hot water circulating pumps and accumulators the calculations for one set of equipment only are shown.

C.2 General Calculations

a) Data Sheet C1/1 is used to calculate and record the capabilities of the main components associated with the fresh water systems.

b) Fresh Water Storage

1) Fresh water storage is based on five days consumption and is currently defined as being 1.0m3 per person in HM Surface Ships, see clause 6.6.1.

c) Filling Rate

1) The filling rate is to be 100m3/h in ships of Frigate/Destroyer size and 50m3/h in ships below Frigate/Destroyer size, see clause 6.6.3.1c).

d) Desalination Requirements

1) The desalination plant capacity is to include an allowance of 200 litres per day per person of complement in HM Surface Ships, see clause 6.3.1b)

2) Additional desalination plant capacity is to be provided when appropriate for gas turbine washing, aircraft washdown, ship husbandry and for feed make–up.

e) Total Number of Outlets

1) Information on the number and size of outlets is to be taken off the diagrammatic arrangement drawings. Outlets which are not in daily use, e.g. emergency supplies to sonar cooling systems and decontamination stations are to be ignored. Showers are counted in both the hot and cold water systems.

f) Total Diversity Factor

1) The total diversity factor is related to the total number of outlets on the vessel. It is determined from Figure 12, clause 6.11.

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g) Design Requirements

1) The size and number of outlets will be as determined at C.2.e)

2) The diversity factor is the total system diversity factor as determined at C.2.f)

3) The flow per outlet is to be taken as shown in Table 7 given in clause 6.11.5e). The outlet of 0.27m3/h for showers is taken 50% from the hot water system and 50% from the cold water system.

h) Design Cold Water Pump Capacity

1) The design cold water pump capacity is to be the total design flow as calculated at Step C.2.g)

i) Design Water Requirements from Boost Pump

2) The conditions which govern the necessity for a boost pump are given in clause 6.11.7a).

3) The diversity factor to be used in calculating the boost pump capacity is to be that appropriate to the number of outlets served by the boost pump and is determined from Figure 8.

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Table C.1 - Calculation Data Sheet C1/1 General Circulation

Installation Typical Complement 460

Part 1 Fresh Water Storage

Storage required by rules = 1.0m3/person = 460 x 1.0 = 460m3

Storage actually fitted = say 460m3

Arrangement 2 groups of tanks (1 forward and 1 aft)

Part 2 Filling Rate

Filling arrangements to be designed for 50m3/h

Part 3 Desalination Requirement

Capacity required by rules (for domestic use) = 0.2m3/person/day = 92m3/day = 3.83m3/h Capacity actually fitted (includes for boiler) = 2 x 4m3/h

Part 4 Total Number of Outlets

Size of Outlet WB 6mm 13mm Shower 19mm Total Cold water system 104 16 74 30 3 227 Hot water system 104 - 31 30 3 168

Total number of outlets 208 16 105 60 6 395

Part 5 Total Diversity Factor

Total number of outlets 365 Diversity factor 0.085

Part 6 Design Requirements (see clause C.2.e))

Size of Outlet Number of Outlets

Diversity factor

Flow per Outlet (m3/h)

Design Flow (m3/h)

6mm 16 0.085 0.07 0.10 WB 208 0.085 0.27 4.77 13mm 105 0.085 0.57 5.09 Showers 60* 0.085 0.14 0.71 19mm 6 0.085 1.63 0.83 395 11.50

*The 60 shower outlets are 30 hot outlets and 30 cold outlets

Part 7 Design Cold Water Pump Capacity Required = 11. 50m3/h

Part 8 Design Water Requirements from Boost Pump (if fitted)

Size of Outlet Number of Outlets

Diversity factor


Design Flow (m3/h)

BOOST PUMP NOT REQUIRED

Part 9 Design Boost Pump Capacity required = 0m3/h

62


C.3 Water Flow and Approximate Pipe Bore Calculation (Cold Water System)

a) Data Sheet C2/1 is used to record the water flow in each pipe section and then to make a preliminary selection of pipe size. It is a necessary prerequisite to this stage that the system line diagram described in clause 6.11.2a) is available.

b) Data Sheet C2/1 records this information for the cold water main when it is being supplied from the aft pump only. Each section is considered as passing the quantity of water required by all the downstream outlet. The flow from the cold water system to each shower is taken as 0.014m3/h (half the total shower flow). A diversity factor determined from Figure 8 is applied to the flow for the number of outlets being supplied.

Table C.2 - Calculation Data Sheet C2/1 Water Flow and Approximate Pipe Bore Calculation

System COLD Piping MAIN Pump in use AFT

1.

Section Reference

2.

Number of Outlets

Downstream

3.

Diversity Factor

4.

Water Flow in Pipe Section (m3/h)

5.

Pipe Size (mm)

Pump to A 395 0.085 Design Flow From Data Sheet C1/1 (Part 7) 11.5

54

A to B 390 0.086 16 x 0.086 x 0.07 = 0.10 208 x 0.086 x 0.27 = 4.83 100 x 0.086 x 0.57 = 4.90 60 x 0.086 x 0.14 = 0.72 6 x 0.086 x 1.63 = 0.84 11.39

54

B to C 389 0.086 As for A to B minus 1 x 0.086 x 0.27 = 0.023 11.39 - 0.02 = 11.37

54

C to D 388 0.087 As for B to C minus 1 x 0.087 x 0.57 = 0.05 11.37 - 0.05 = 11.32

54

D to E 338 0.087 16 x 0.087 x 0.07 = 0.10 179 x 0.087 x 0.27 = 4.20 88 x 0.087 x 0.57 = 4.36 50 x 0.087 x 0.14 = 0.61 5 x 0.087 x 1.63 = 0.71 9.98

54

T to U

c) A preliminary pipe bore is selected on the basis of passing the required quantity of water at a reasonable speed and without excessive pressure loss. Table 4 will be of assistance as it shows the maximum flow in each size of pipe. In order to provide some slack in the system and to permit the passage of enhanced flow when required it is recommended that water speeds in mains should generally be restricted to 50% to 70% of the maximum permitted.

d) The filling and transfer lines, which are used only intermittently and in which pressure drop is of secondary importance, may be selected to operate at the highest permissible water speed.

63

Def Stan 02-728 Issue 3 e) Data Sheet C2/2 records the information on the cold water main when it is being supplied from the

forward pump only. The information recorded is similar to that on Data Sheet C2/1 for the use of the aft pump.

f) For some sections the size of pipe initially determined in the calculations on Data Sheet C2/1 and C2/2 will not be the same. The larger of the two sizes is to be selected.


System COLD Piping MAIN Pump in use FORWARD

1.

Section Reference

2.

Number of Outlets

Downstream

3.

Diversity Factor

4.

Water Flow in Pipe Section

(m3/h)

5.

Pipe Size

(mm)

Pump to U 395 0.085 Design Flow From Data Sheet C1/1 (Part 7) 11.5

54

U to T 307 0.087 16 x 0.087 x 0.07 = 0.10 208 x 0.087 x 0.27 = 3.45 101 x 0.087 x 0.57 = 5.01 37 x 0.087 x 0.14 = 0.45 6 x 0.087 x 1.63 = 0.85 9.86

54

T to S 301 0.088 16 x 0.088 x 0.07 = 0.10 144 x 0.088 x 0.27 = 3.42 98 x 0.088 x 0.57 = 4.92 37 x 0.088 x 0.14 = 0.46 6 x 0.088 x 1.63 = 0.86 9.76

54

S to R etc. E to D 57 0.19 29 x 0.19 x 0.27 = 1.49

17 x 0.19 x 0.57 = 1.84 10 x 0.19 x 0.14 = 0.27 1 x 0.19 x 1.63 = 0.31 3.91

54

B to A

g) Data Sheet C2/3 records information on the branches corresponding to that for the main recorded in calculations on Data Sheets C2/1 and C2/2.

h) At this stage there should be a check to confirm that the pipe sizes selected for the main and branches will be capable of giving an adequate supply to any particularly large users. It should also be remembered that there are special requirements for the size of pipes supplying groups of showers and wash-basins.

64


Table C.4 - Calculation Data Sheet C2/3

Water Flow and Approximate Pipe Bore Calculation

System COLD Piping BRANCHES Pump in use Aft or FORWARD

1. Section

Reference

2. Number of

Outlets Downstream

3. Diversity

Factor

4. Water Flow in Pipe Section

(m3/h)

5. Pipe Size

(mm)

A to 1 5 0.84 5 x 0.84 x 0.57 = 2.39 28 B to 2 1 1.0 1 x 1.0 x 0.27 = 0.27 12 C to 2.1 1 1.0 1 x 1.0 x 0.57 = 0.57 15 D to 3 50 0.20 28 x 0.20 x 0.27 = 1.51

11 x 0.20 x 0.57 = 1.25 10 x 0.2 x 0.14 = 0.24 1 x 0.2 x 1.63 = 0.33 3.33

35

3 to 4 18 0.44 12 x 0.44 x 0.27 = 1.43 5 x 0.44 x 0.14 = 0.31 1 x 0.44 x 0.57 = 0.25 1.99

28

4 to 5 17 0.46 11 x 0.46 x 0.27 = 1.37 5 x 0.46 x 0.27 = 0.62 1 x 0.46 x 0.57 = 0.26 2.25

28

5 to 6 12 0.57 11 x 0.57 x 0.27 = 1.69 1 x 0.57 x 0.57 = 0.32 2.01

28

6 to 7 7 to 8 D to 7 F to 8 U to 55

NOTE The above details are to be completed for all branches

65


C.4 Physical Data (Cold Water System)

a) Data Sheet C3/1 is used to record the physical characteristics of the piping systems. Before it can be prepared it is necessary to have available the piping diagram on ship deck plans described in clause 6.11.2f).

b) Data Sheet C3/1 records the physical data for the cold water main starting at the aft tank and working forward.

Table C.5 - Calculation Data Sheet C3/1 Physical Data

System COLD Piping MAIN Pump in use Aft

1. Section

Reference

2. Length

(m)

3. Elbows

4. Tee–pieces (Flow Past)

5. Tee–pieces

(Flow Round)

6. Other

Fittings

7. Stop Cocks and Valves

Tank to Pump 5.0 3 1 2 1 Strainer 1 NRV Pump to A 2.4 2 3 - 1 Strainer 2 Ball A to B 1.2 - - 1 - - B to C 2.5 - 1 - - - C to D 1.0 - 1 - - - D to E 7.3 - 1 - - - E to F 6.4 - 1 - - - F to G 34.5 1 2 1 - - G to H 0.6 - 1 - - - H to J 3.1 - 1 - - - J to K 3.9 - 1 - - - K to L 0.6 - 1 - - - L to M 2.5 - 1 - - - M to N 7.9 - 1 - - - N to P 2.5 - 1 - - - P to Q 5.4 - 1 - - - R to S 10.9 - 1 - - - S to T 15.1 - 1 - - - T to U 4.2 1 - 1 - -

c) Data Sheet C3/2 records the physical data for the cold water main, starting at the forward tank and working aft. For intermediate sections the data recorded will be identical with that on Data Sheet C3/1 but listed in the reverse order.

66



Physical Data

System COLD Piping MAIN Pump in use FORWARD

1. 2. 3. 4. 5. 6. 7. Section Reference Length

(m) Elbows Tee–pieces

(Flow Past)Tee–pieces

(Flow Round) Other

Fittings Stop Cocks and Valves

Tank to Pump 5.0 3 1 1 1 Strainer 1 NRV Pump to U 9.6 3 4 1 1 Strainer 2 Ball U to T 4.2 1 - 1 - - T to S 15.1 - 1 - - - S to R 10.9 - 1 - - - R to Q 3.6 - 1 - - - Q to P 5.4 - 1 - - - P to N 2.5 - 1 - - - N to M 7.9 - 1 - - - M to L 2.5 - 1 - - - L to K 0.6 - 1 - - - K to J 3.9 - 1 - - - J to H 3.1 - 1 - - - H to G 0.6 - 1 - - - G to F 34.5 1 2 1 - - F to E 6.4 - 1 - - - E to D 7.3 - 1 - - - D to C 1.0 - 1 - - - C to B 2.5 - 1 - - - B to A 1.2 - - 1 - -

NOTE Data Sheet C3/3 records the physical data for the cold water system branches.


System COLD Piping BRANCHES Pump in use Aft or FORWARD

1. 2. 3. 4. 5. 6. 7. Section Reference Length


(Flow Past) Tee–pieces

(Flow Round) Other


A to 1 19.4 4 4 1 - 1 B to 2 2.1 1 - 1 - 1 C to 2.1 5.0 2 - 1 - 1 D to 3 2.7 1 - 1 - 1 3 to 4 10.9 3 4 - - - 4 to 5 1.5 - - 1 - - 5 to 6 1.8 2 1 - - - D to 7 11.5 2 - 1 - 1 E to 8 4.8 1 - 1 - 1 F to 9 9 to 10 40 to 42 19.7 2 + 6,

45° 1 1 - 1

U to 55

NOTE The above details are to be completed for all branches of the system.

67


C.5 Pipe Friction Calculations (Cold Water System Main)

a) Data Sheet C4/1 is used for calculating the piping system pressure loss. It has been designed for use with the equivalent length method of determining the pressure loss of valves and fittings. The use of this system is justified because of the continuous variation in flow that occurs.

b) Calculations on Data Sheet C4/1 determines the pressure loss in the cold main when the aft pump is in use.

c) The information on this Data Sheet is derived as follows:

Column 1 - Pipe section reference;

Column 2 - The design water flow from Data Sheet C2/1;

Column 3 - The system components from Data Sheet C3/1;

Column 4 - Equivalent length coefficients for the components. These are listed in Table 5, clause 6.11;

Column 5 - Pipe bore, the initial selection has been made on Data Sheet C2/1;

Column 6 - Is used to calculate the equivalent length of the system components;

Column 7 - Actual length of pipe taken from Data Sheet C3/1;

Column 8 - Column 6 added to Column 7;

Column 9 & 10 - Are read from the Pressure Loss Chart, Figure 6, clause 6.11. The head loss in column 10 recorded (in bar) is for 1m length of pipe;

Column 11 - Column 10 multiplied by the total equivalent length given in Column 8;

Column 12 - The static pressure drop (in bar) due to the height of the end of the pipe section above datum. The datum is to be taken as the bottom of the fresh water tank relative to the pump being considered;

Column 13 - The total head loss (in bar) from the bottom of the fresh water storage tank to the end of the pipe section being considered. This is obtained from the sum of the friction head losses in the pipe sections along the flow route and the height of the pipe section above the datum.

d) Calculations on Data Sheet C4/2 determine the pressure loss in the cold main when the forward pump is in use. Information and data for Columns 2 and 5 are taken from Data Sheet C2/2 and for Columns 3 and 7 from Data Sheet C3/2.

68



Pipe Friction Calculations

System COLD Piping Main Pump in use Aft 13

.

Tota

l Los

s to

Se

ctio

n (b

ar)

0.11

+ 0

.18

= 0

.29

0.11

+ 0

.04+

0.4

3 =

0.58

0.58

+ 0

.025

=

0.60

5

0.60

5 +

0.01

3 =

0.61

8

12.

Hei

ght

Abo

ve

Dat

um

(bar

)

0.18

0.43

0.43

11.

Sect

ion

Loss

(b

ar)

0.00

56 x

18.

8 =0

.11

0.00

56 x

7.1

=0

.04

0.00

54 x

4.7

=0

.025

0.00

53 x

2.5

=0

.013

10.

Hea

d Lo

ss

(bar

/m)

0.00

56

0.00

56

0.00

54

0.00

53

9.

Wat

er

Spee

d (m

/s)

1.62

1.62

1.61

1.60

8.

Tota

l Eq

uiva

lent

Le

ngth

(m)

18.8

7.1

4.7

2.5

7.

Act

ual

Leng

th

(m)

5.0

2.4

1.2

2.5

6.

Com

pone

nt

Equi

vale

nt

Leng

th

K x

D

1000

13.8

4.7

3.5 -

5.

Pipe

B

ore

D

(mm

)

50

50

50

50

=

36

= 1

40

=

40

=

60

= 2

76

=

24

=

40

=

30

=

94

=

70

=

70

4.

Equi

vale

nt

Leng

th

Coe

ffici

ent K

12 x

3

- 70

x 2

40

x 1

60

x 1

To

tal

12 x

2

- 40

x 1

15

x 2

To

tal

70 x

1

Tota

l

-

3 1 2 1 1 2 3 1 2 1 1

3.

Syst

em

Com

pone

nts

Elb

ows

Tee

s (fl

ow p

ast)

Tee

s (F

low

roun

d)

Stra

iner

s N

R V

alve

s

Elb

ows

Tee

s (fl

ow p

ast)

Stra

iner

s B

all V

alve

s

Tee

s (F

low

roun

d)

Tee

s (F

low

pas

t)

2.

Flow

(m

3 /h)

11.5

11.5

11.3

9

11.3

7

1.

Sect

ion

Ref

eren

ce

Tan

k to

Pum

p

Pum

p to

A

A to

B

B to

C

C to

D

D to

E

T to

U

NOTE The above details are to be completed for all sections of piping.

69


Table C.9 - Calculation Data Sheet C4/2 Pipe Friction Calculations

System COLD Piping Main Pump in use FORWARD

13.

Tota

l Los

s to

Se

ctio

n (b

ar)

0.18

+ 0

.086

=

0.2

66

0.08

6 +

0.10

3 +

0.43

=

0.6

19

0.18

9 +

0.03

5 +

0.67

=

0.8

94

0.89

4 +

0.06

3 =

0.9

57

1.02

6* +

0.0

006

= 1.

032

12.

Hei

ght

Abo

ve

Dat

um

(bar

)

0.18

0.43

0.67

0.67

0.43

* Es

timat

ed v

alue

11.

Sect

ion

Loss

(bar

)

0.00

56 x

15.

3 =

0.0

86

0.00

56 x

18.

4 =

0.10

3

0.05

6 x

8.3

= 0

.035

0.00

42 x

15.

1 =

0.06

3

0.00

078

x 7.

3 =

0.00

6

10.

Hea

d Lo

ss

(bar

/m)

0.00

56

0.00

56

0.00

42

0.00

42

0.00

078

9.

Wat

er

Spee

d (m

/s)

1.62

1.62

1.38

1.36

0.53

8.

Tota

l Eq

uiva

lent

Le

ngth

(m)

15.3

18.4

8.3

15.1

7.3

7.

Act

ual

Leng

th

(m)

5.0

9.6

4.2

15.1

7.3

6.

Com

pone

nt

Equi

vale

nt

Leng

th

K x

D

1000

10.3

8.8

4.1 - -

5.

Pipe

B

ore

D

(mm

)

50

50

50

50 50

= 3

0 =

70

= 4

0 =

60

= 20

0

= 3

6 - =

70

= 4

0 =

30

= 17

6

= 1

2 =

70

= 8

2

4.

Equi

vale

nt

Leng

th

Coe

ffici

ent K

10 x

3

- 70

x 1

40

x 1

60

x 1

To

tal

12 x

3

- 70

x 1

40

x 1

15

x 2

To

tal

12 x

1

70 x

1

Tota

l

- -

3 1 1 1 1 3 4 1 1 2 1 1 1 1

3.

Syst

em

Com

pone

nts

Elb

ows

Tee

s (fl

ow p

ast)

Tee

s (F

low

roun

d)

Stra

iner

s N

R V

alve

s

Elb

ows

Tee

s (fl

ow p

ast)

Tee

s (F

low

roun

d)

Stra

iner

s B

all V

alve

s

Elb

ows

Tee

s (F

low

pas

t) T

ees

(Flo

w p

ast)

Tee

s (F

low

pas

t)

2.

Flow

(m

3 /h)

11.5

11.5

9.86

9.76

3.91

1.

Sect

ion

Ref

eren

ce

Tan

k to

Pum

p

Pum

p to

U

U to

T

T to

S

S to

R

R to

Q

E to

D

B to

A


70


C.6 Pipe Friction Calculations (Cold Water System Branches)

a) Calculations on Data Sheet C4/3 continue the pressure drop calculation with determination of the loss in the branches with either pump in use. Information and data are taken from Data Sheets C2/3 and C3/3.

b) The pressure drop to the start of each branch is different for the aft pump than for the forward pump. Additionally in this example, the aft and forward storage tanks are at different levels. It is therefore necessary to make separate calculations of total pressure drop for either pump in use.

c) At the conclusion of these calculations, comparison of the pressure drop in each branch is to be made to determine if it would be possible to make the pressure drops more equal. This will involve the use of increased water speed in branches on lower decks. Care must be taken not to exceed the water speeds given in Table 4 (see clause 6.11.8a)) and to provide a pipe of the correct size for supplying wash-basins and showers (see Def Stan 02-120 (for legacy fit) and MAP 01-107 Parts 1 & 2 for new design vessels).

d) A note is to be made of all wash-basins and showers on the cold water system which have a pressure greater than 2 bar. These outlets are to be fitted with an orifice as described in clause 6.11.8b).

71



System COLD Piping Branches Pump in use AFT & FORWARD

13.

Tota

l Los

s to

Se

ctio

n (b

ar)

0.58

+ 0

.22

=

0.80

1.

23*

+ 0.

22

= 1

.45

0.60

5 +

0.04

7 =

0.6

52

1.11

2* +

0.0

47

= 1

.159

2.24

2* +

0.0

64

= 2

.306

2.

441*

+ 0

.064

=

2.5

05

12.

Hei

ght

Abo

ve

Dat

um

(bar

)

A 0

.43

F

0.67

A 0

.43

F

0.67

A 1

.65

F

1.89

11.

Sect

ion

Loss

(b

ar)

0.00

8 x

27.4

=

0.2

2

0.01

3 x

3.6

= 0

.047

0.00

28 x

22.

8 =

0.06

4

* E

stim

ated

Val

ue

A

Flow

from

Aft

pum

p

F Fl

ow fr

om fo

rwar

d pu

mp

10.

Hea

d Lo

ss

(bar

/m)

0.00

8

0.01

3

0.00

28

9.

Wat

er

Spee

d (m

/s)

1.32

0.88

0.59

8.

Tota

l Eq

uiva

lent

Le

ngth

(m)

27.4

3.6

22.8

7.

Act

ual

Leng

th

(m)

19.4

2.1

19.7

6.

Com

pone

nt

Equi

vale

nt

Leng

th

K x

D

1000

8.0

1.5

3.1

5.

Pipe

B

ore

D

(mm

)

25.6

10.4

19.6

= 4

8 =

250

= 1

5 =

313

= 1

2 =

120

= 1

5 =

147

= 2

4 =

48

= 7

0 =

15

= 15

7

4.

Equi

vale

nt

Leng

th

Coe

ffici

ent K

12 x

4 -

250

x 1

15 x

1

Tota

l

12 x

1

120

x 1

15 x

1

Tota

l

12 x

2

8 x

6 - 70

x 1

15

x 1

To

tal

4 4 1 1 1 1 1 2 6 1 1 1

3.

Syst

em C

ompo

nent

s

Elb

ows

Tees

(flo

w p

ast)

Tees

(Flo

w ro

und)

B

all v

alve

Elb

ows

Tees

(Flo

w ro

und)

B

all V

alve

s

Elb

ows

Ben

d (4

5o ) Te

es (f

low

pas

t) Te

es (F

low

roun

d)

Bal

l val

ve

2.

Flow

(m

3 /h)

2.39

0.27

0.64

1.

Sect

ion

Ref

eren

ce

A to

1

B to

2

C to

2.1

D to

3

3 to

4

40 to

42

R to

43

U to

55


72


C.7 Selection of Cold Water Pump and Cold Water Boost Pump

a) Data Sheet C5 is used for the selection of the cold water pump and cold water boost pump. These pumps are not used in Submarines.

b) Information on the selection of cold water and boost pumps is given in clause 6.7.

c) Data Sheet C5 is filled in as follows:

1) The cold water pump capacity required is to be table from Data Sheet C1/2;

2) The differential pressure required from the pump is to be the pressure loss in the system as determined in Data Sheet C/4, with 10% safety margin and the addition of the pressure required at the highest point, this is to be taken as 0.35 bar unless there is a specific requirement for a greater pressure, e.g. Bridge Window Washer System 1.4 bar and head lift above main to windows. See also clause 6.3.1d);

3) On ships of Frigate/Destroyer size and above four pumps are required, on ships smaller than these two pumps are required.

d) The necessity for a cold water boost pump will have been determined in Data Sheet C1/2. The pressure development required is taken from Data Sheet C4/-, Column 13.

73


Table C.11 - Calculation Data Sheets C5 Selection of Cold Water Pump and Cold Water Boost Pump

1) Cold Water Pump

i) Cold Water Pump Capacity Required (Data Sheet C1/1) = 11.5m3/h Pressure: Maximum Pressure Loss in System (Data Sheet C4/-, Column 13) = 2.51 bar + 10% margin = 2.76 bar Minimum Pressure Required at Highest/ Most Remote Point (if height is involved the = 0.35 bar head lift must also be added) Differential Pressure Required from Pump = 2.69 + 0.35 = 3.04 bar

ii) Number of Pumps Required by Rules (see Clause 6.11.2l)) = 2

iii) Pump Duty (100% Standby on Diversity Factor) see clause 6.7 Output = 12m3/h Differential Pressure = 3.04 bar

iv) Pump Arrangement 1 Forward 1 Aft – Amidships

v) Pumps Actually Fitted

2) Cold Water Boost Pump

i) Not Required;

ii) Output (Data Sheet C1/1) = m3/h

iii) Pressure: Maximum Pressure Loss in System bar (Data Sheet C4/-, Column 13) Minimum Pressure Required at Highest/Most Remote Point (see above) = 0. 35 bar Differential Pressure Required from Pump = +0.35 = bar

iv) Location

74


C.8 Water Flow Rates From Calorifiers

a) Data Sheet C6 is used to calculate the total hot water heat load and the distribution of this load between the calorifiers.

b) The hot water required on HM Surface Ships is 0.012m3/h per person and this requires a heater of 0.77 kW per person. (see clause 6.11.10b)).

c) The number and type of outlet on each of the hot water systems are determined and the diversified flow for each system calculated using Figure 8, clause 6.11.

d) The total required heating capacity is to be allocated between the hot water systems in proportion to their diversified flow. The calculated heating power is rounded up to the nearest convenient value.

e) The storage capacity is required to be determined by using the information given in clauses 6.11.12a) or 6.11.12b) and Figure 10 to Figure 14 inclusive.

f) It will be noted that in the example the forward calorifier, which serves mainly showers and wash-basins, has a heating capacity per outlet that is lower than the other two systems. Because of this low heating rate and the fact that showers may be used continuously for substantial periods the storage capacity of the forward system has been made proportionally greater.

75


Table C.12 - Calculation Data Sheet C6 Hot Water Flow from Calorifiers

Heat Requirement

Complement 460

Total hot water required at 0.012m3/h per person 5.52m3/h

Total Calorifier heating capacity at 0.77 kW/person 354 kW

Design Requirements

System Aft Diversity Factor 0.29

Type of Outlet Number of Outlets

Diversity Factor


Design Flow (m3/h)

WB 16 0.29 0.27 1.25 13 mm 10 0.29 0.57 1.65 Showers 5 0.29 0.14 0.20 19 mm 1 0.29 1.63 0.47 32 3.57

System Midships Diversity Factor 0.16


Diversity Factor


Design Flow (m3/h)

6 mm & WB 45 0.16 0.27 1.94 13 mm 18 0.16 0.57 1.64 Showers 10 0.16 0.14 0.22 19 mm 2 0.16 1.63 0.52 75 4.32

System Forward Diversity Factor 0.18


Diversity Factor


Design Flow (m3/h)

6 mm & WB 43 0.18 0.27 2.09 13 mm 3 0.18 0.57 0.31 Showers 15 0.18 0.14 0.38 19 mm - 61 2.78

Total Diversified Flow = 3.57 + 4.32 + 2.78 = 10.67 m3/h

Heat Required aft calorifier 354 x 3.57 B 10.67 = 118.44 kW Heat Required midships calorifier 354 x 4.32 B 10.67 = 143.32 kW Heat Required forward calorifier 354 x 2.78 B 10.67 = 92.23 kW

Calorifiers Selected

Aft calorifier 0.455m3 120 kW Midships calorifier 0.455m3 150 kW Forward calorifier 0.455m3 100 kW

76


C.9 Water Flow and Approximate Pipe Bore Calculation (Hot Water System)

a) Data Sheet C7/1 is used to record the number of outlets downstream of each section of the hot water ring main and the flow in the section after the application of the diversity factor. A preliminary selection is made of the pipe bore. It is only necessary to work round the system in one direction as the non–return valve prevents reverse flow.

b) Calculations on Data Sheet C7/1 show the characteristics of the aft system.


System AFT or HOT Piping RING MAIN Pump in use FORWARD (Aft Calorifier)

1. Section

Reference

2. Number of

Outlets Downstream

3. Diversity

Factor

4. Water Flow in Pipe Section

(m3/h)

5. Pipe Size

(mm)

Calorifier to A

32 0.29 From Table C.12 Design requirements System AFT = 3.57

35

A to B 14 0.52 4 x 0.52 x 0.27 = 0.56 9 x 0.52 x 0.57 = 2.67 1 x 0.52 x 1.63 = 0.85 4.08

35

B to C 13 0.54 3 x 0.54 x 0.27 = 0.44 9 x 0.54 x 0.14 = 0.68 1 x 0.54 x 1.63 = 0.88 2.00

35

C to D 12 0.57 3 x 0.57 x 0.27 = 0.46 8 x 0.57 x 0.57 = 2.60 1 x 0.57 x 1.63 = 0.93 3.99

35

D to E K to Calorifier

NOTE The above details are to be completed for all sections of the ring main.

77


C.10 Water Flow and Approximate Pipe Bore Calculation

Data Sheet C7/2 is used to record the water flow and initial selection of pipe bore for the hot water system branches on the aft system.


System AFT or HOT Piping BRANCHES Pump in use FORWARD

1. 2. 3. 4. 5. Section

Reference Number of

Outlets Downstream

Diversity Factor

Water Flow in Pipe Section Pipe Size

(m3/h) (mm) A to 1 17 0.46 11.0 x 0.46 x 0.27 = 1.37

1.0 x 0.46 x 0.57 = 0.26 5.0 x 0.46 x 0.14 = 0.32 1.95

28

1 to 2 11 0.57 11 x 0.57 x 0.27 = 1.69 1.69

28

B to 4 1 1.0 1 x 1 x 0.27 = 0.27 12 C to 5 1 1.0 1 x 1 x 0.57 = 0.57 15 D to 6 E to 7 F to 8 K to 13 1 1 1 x 1 x 0.57 = 0.57 15

NOTE The above details are to be completed from all Sections from the piping main.

C.11 Physical Data (Hot Water System)

Data Sheet C8/1 is used to record the physical data for the hot water ring main for the aft hot water system.


System AFT or HOT Piping MAIN Pump in use FORWARD (Aft Calorifier)

1. Section

Reference

2. Length

(m)

3. Elbows

4. Tee–pieces (Flow Past)

5. Tee–pieces

(Flow Round)

6. Other

Fittings

7. Stop Cocks and

Valves Calorifier to A

1.3 1 - - - 1

A to B 5.4 1 1 1 - - B to C 2.4 - 1 1 - - C to D 6.7 1 1 1 - - D to E 21.2 2 1 - - - E to F 0.6 - 1 - - - F to G 6.7 1 1 1 - - G to H 10.3 1 1 - - - H to J 9.7 1 1 - - - J to K 4.2 - 1 - - - K to Calorifier

53.3 8 3 - - -


78


C.12 Physical Data For Hot Water Branches (Aft)

Data Sheet C8/2 is used to record the physical data for the hot water branches in the aft hot water system.


System AFT or HOT Piping BRANCHES Pump in use FORWARD (Aft Calorifier)

1. 2. 3. 4. 5. 6. 7. Section

Reference Length


(Flow Past) Tee–pieces

(Flow Round) Other


A to 1 5.8 3 1 - - 1 1 to 2 7.9 3 3 1 - - 1 to 3 5.5 3 1 1 - - B to 4 3.0 2 - 1 - 1 C to 5 0.6 1 - 1 - 1 D to 6 3.0 1 1 1 - 1 E to 7 0.6 1 - 1 - 1 F to 8 6.1 4 - 1 - 1 F to 9 7.9 2 3 - - 1 G to 10 1.2 1 - 1 - 1 H to 11 3.0 3 1 1 - 1 J to 12 2.4 3 1 1 - 1 K to 13 2.4 1 - 1 - 1


C.13 Pipe Friction Calculations (Hot Water System Main)

a) Data Sheet C9/1 is used to calculate the pressure drop around the aft hot water system ring main.

b) The procedure is the same as that used for the cold water system. However, the pipe resistance is to be taken from Figure 7, and clause 6.11.

79




13.

Tota

l Los

s to

Sec

tion

(bar

)

0.01

0.01

+ 0

.053

+0.

24

= 0.

303

0.30

3 +

0.02

6 =0

.329

12.

Hei

ght

Abo

ve

Dat

um

(bar

)

0

0.24

0.24

11.

Sect

ion

Loss

(b

ar)

0.0

044

x 2.

2 =

0.0

1

0.0

055

x 9.

6 =

0.0

53

0.0

056

x 4.

6 =

0.0

26

10.

Hea

d Lo

ss

(bar

/m)

0.00

44

0.00

55

0.00

56

9.

Wat

er

Spee

d (m

/s)

1.23

1.41

1.41

8.

Tota

l Eq

uiva

lent

Le

ngth

(m)

2.2

9.6

4.6

7.

Act

ual

Leng

th

(m)

1.3

5.4

2.4

6.

Com

pone

nt

Equi

vale

nt

Leng

th

K x

D

1000

0.9

4.2

2.2

5.

Pipe

B

ore

D

(mm

)

32

32

32

=

12

=

15

=

27

=

12

= 1

20

= 1

32

=

70

=

70

4.

Equi

vale

nt

Leng

th

Coe

ffici

ent K

12

x 1

1

5 x

1 T

otal

12

x 1 -

120

x 1

T

otal

- 7

0 x

1 T

otal

m

1 1 1 1 1 1 1

3.

Syst

em

Com

pone

nts

Elb

ows

Bal

l val

ve

Elb

ows

Tee

s (F

low

pas

t) T

ees

(Flo

w ro

und)

T

ees

(Flo

w p

ast)

Tee

s (F

low

roun

d)

2.

Flow

(m

3 /h)

3.57

4.08

4.09

1.

Sect

ion

Ref

eren

ce

Cal

orifi

er to

A

A to

B

B to

C

C to

D

D to

E

J to

K


80


C.14 Pipe Friction Calculations (Hot Water System Branches)

Data Sheet C9/2 is used to calculate the pressure drop in the aft hot water system branches.



13.

Tota

l Los

s to

Se

ctio

n (b

ar)

0.03

0.03

+ 0

.037

=

0.0

67

1.02

* +

0.04

8 =

1.0

68

12.

Hei

ght

Abo

ve

Dat

um

(bar

)

0 0

0.73

* E

stim

ated

val

ue

11.

Sect

ion

Loss

(b

ar)

0.00

42 x

7.1

=

0.0

3

0.00

35 x

10.

6 =

0.0

37

0.01

3 x

3.7

= 0

.048

10.

Hea

d Lo

ss

(bar

/m)

0.00

42

0.00

35

0.01

3

9.

Wat

er

Spee

d (m

/s)

1.05

0.95

1.18

8.

Tota

l Eq

uiva

lent

Le

ngth

(m)

7.1

10.6

3.7

7.

Act

ual

Leng

th

(m)

5.8

7.9

2.4

6.

Com

pone

nt

Equi

vale

nt

Leng

th

K x

D

1000

1.3

2.7

1.3

5.

Pipe

B

ore

D

(mm

)

25.6

25.6

13.0

6

=

36

=

15

=

51

=

36

=

70

= 1

06

=

12

=

70

=

15

=

97

4.

Equi

vale

nt

Leng

th

Coe

ffici

ent K

12

x 3

-

15

x 1

Tot

al

12

x 3

- 7

0 x

1 T

otal

12

x 1

m

70

x 1

15

x 1

Tot

al

3 1 1 3 3 1 1 1 1

3.

Syst

em

Com

pone

nts

Elb

ows

Tee

s (F

low

pas

t) B

all v

alve

Elb

ows

Tee

s (F

low

pas

t) T

ees

(Flo

w ro

und)

E

lbow

s T

ees

(Flo

w ro

und)

B

all v

alve

s

2.

Flow

(m

3 /h)

1.95

1.69

0.57

1.

Sect

ion

Ref

eren

ce

A to

1

1 to

2

K to

13

C to

5

B to

4


81


C.15 Pressures Required and Available at Calorifier(s)

a) Data Sheet C10 is used to calculate the pressures that are required and are available at the aft calorifier.

b) The pressure loss to the most remote point of the system will have been calculated on Data Sheet C9/-. To this must be added a 10% safety margin and the pressure required at the outlet (0.35 bar) to give the pressure required at the calorifier inlet.

c) The pressure available at the calorifier with either of the two pumps in use will have been determined as part of the analysis of the cold water system.

d) Data Sheet C10 includes a section for determining the requirement for a hot water boost pump. As stated in clause 6.7.5, a hot water boost pump is not to be fitted unless its use is completely unavoidable. The following alternative arrangements are to be considered:

1) The use of separate single outlet electric water heaters supplied from the cold water boost pump system.

2) The use of separate hot water system supplied from the cold water boost pump.

e) Similar calculations are to be made for each of the hot water systems on the ship.

82


Table C.19 - Calculation Data Sheet C10

Pressures Required and Available at Calorifier(S)

1) Calorifier Position After Compartment

2) Pressure Required Maximum Pressure Loss in System = 1. 07 + 10% = 1.18 bar Minimum Pressure Required at Highest/Most Remote Point = 0.35 bar = 0.35 bar Pressure Required at Calorifier Inlet = 1.18 + 0.35 = 1.53 bar

3) Pressure Available

i) Cold Water Pump in Use Aft Pressure Available at Calorifier 2.47 bar *

ii) Cold Water Pump in Use Forward Pressure Available at Calorifier 1.72 bar *

4) Hot Water Boost Pump

i) Not Required

ii) Output (Data Sheet C7/-) = m3/h

iii) Pressure Maximum Pressure Loss in System (Data Sheet C9, Column 13) = bar Minimum Pressure Required at Highest/Most Remote Point = 0.35 bar = 0.35 bar Differential Pressure Required from Pump = + 0.35 = bar

iv) Location

* Estimated Value

C.16 Duty of Hot Water Circulating Pump

a) Data Sheet C11 is used to determine if a hot water circulating pump is required.

b) The vertical lift of the hot and cold legs of the hot water ring main is determined from the arrangement drawings.

83

Def Stan 02-728 Issue 3 c) Clause 6.11.9b) gives the maximum equivalent length of each size of pipe through which it is possible

to maintain adequate thermal circulation for each metre of vertical lift.

d) The equivalent length of the ring main is determined using the same procedures as those used in Data Sheet C9. If the system total equivalent length is greater than can be sustained by the available vertical lift then a circulating pump is to be fitted.

e) If a circulating pump is required it is to be capable of maintaining a water speed round the ring main to keep the main at the required temperature. The pressure development required by the pump is determined by completing Data Sheet C9 for the ring piping at the required circulation rate.

f) Similar calculations are to be made for each of the hot water systems on the ship.

g) Details of the standard range hot water circulation pump are given in clause 6.7.4c).

h) The circulating rate required is determined from the formulae:

kWL2K

LossHeat

rrLog

TT

1

2e

12 −π=

Where K = Thermal conductivity of piping insulation = 2.3 x 10-5 kW/m2 °C/m thickness L = Length of piping in metre T1 = Hot water temperature = 70°C T2 = Ambient temperature = 15°C r1, r2 = Inside and outside radius of piping insulation in consistent units

81.5LossHeatRategCalculatin = m3/h

84


Table C.20 - Calculation Data Sheet C11

Duty of Hot Water Circulating Pump

Calorifier After

Hot and cold leg vertical lift 4.9m

Size of piping in ring main 34mm

Maximum ring main equivalent length for natural circulation (see clause 6.11.9b)) 4.9 x 25 = 122.5m

Resistance of Ring Main

System Components Equivalent Length Coefficient

Pipe Bore (mm)

Component Equivalent Length (m)

Bends 26 12 x 26 = 312 612 x 321000

Valves, ball 2 15 x 2 = 30

Valves, NR 1 60 x 1 = 60 Tees (flow round) 3 70 x 3 = 210 32 = 19.58 Tees (flow past) 7 — 612

TOTAL 19.58 Actual Pipe Length (see Data Sheet C 8/1) 121.8

Total Equivalent System Length 141.38

Natural circulation not possible

Hot Water Circulating Pump

81.5x

Lxp2xK81.5

)kW(lossHeat

rrLog

TT

1

2e

12 −==Circulation rate

23.081.5x

5.175.36

1570x8.121xp2xx3.2

log10

e

5

=−

=−

m3/h

C.17 Capacity of Accumulators

a) Data Sheet C12 is used for the selection of accumulators; one accumulator is to be used in each hot water system. A separate Data Sheet is to be used for the selection of each accumulator.

b) The volume of the water in the ring main and calorifier is to be determined. Pipe capacity may be taken from Table 4 Clause 6.11. Data Sheet C11 gives the volume of the calorifier.

c) The required capacity of the accumulator is 5% of the total ring main plus the calorifier capacity.

d) Details of standard range accumulators are given in clause 6.10.1, Table 3.

85


Table C.21 - Calculation Data Sheet C12 Capacity of Accumulators

Calorifier After

Volume of water in ring main

Pipe Bore Pipe Length Weight of Water Total Weight of Water (mm) (m) (kg/m) (kg)

32 121.8 0.81 98.7 98.7

3 Total volume, Weight B 1000 m = 0.099m3

Calorifier volume = 0.200m3*

Total system volume = 0.299m3

1) Capacity of Accumulator The accumulator capacity is to be 5% of the total Capacity required = 0.299m3 x 5% = 0.015m3

* Estimated value

C.18 For the purposes of this def Stan the following Formulae apply:

unitsSIingn.d

PessurePrFluidH =a) Fluid Head

Where H = Head (m) P = Pressure (N/m2)(1 bar = 105 N/m2) gn = Gravitational acceleration (9.81 m/s2) d = Density (kg/ m3)

b) NPSH Required HVH vap2

s gn2NPSH −+=

Where Hs = absolute static head suction (m) V = velocity of fluid in pump impeller eye (m/s) Hvap = vapour pressure of fluid expressed as a head (m) gn = Gravitational acceleration (9.81 m/s2)

HVHNSPH vap

2

sfsfsf gn2

−+=c)

Where Hsf = absolute static head at pump suction flange (m0 Vsf = velocity of fluid at the pump suction flange (m/s) Hvap = vapour pressure of fluid expressed as a head (m) gn = Gravitational acceleration (9.81 m/s2)

86


Annex D Types of Backflow Preventor

TYPE & PURPOSE DESCRIPTION INSTALLED AT EXAMPLES

Main supply lines Commercial boilers Hospital equipment Processing tanks Laboratory equipment Waste digesters Sewage treatment

REDUCED PRESSURE ZONE BACKFLOW PREVENTER For high hazard cross connections and continuous pressure applications

Two independent check valves with intermediate relief valve. Supplied with shut off valves and ball type test cocks.

All cross connections subject to backpressure or back siphonage where there is a high potential health hazard from contamination. Continuous pressure.

1

Main supply lines Food cookers Tanks and vats Fire sprinkler lines

DOUBLE CHECK VALVE ASSEMBLY For low hazard cross connections and continuous pressure applications

Two independent check valves. Supplied with shut off valves and ball type test cocks.

All cross connections subject to backpressure or back siphonage where there is low potential health hazard from contamination. Continuous pressure.

DOUBLE DETECTOR CHECK VALVE BACKFLOW PREVENTERS For low and high hazard dependent on type

Double check valve backflow preventors with a water meter and double check or by-pass line.

Fire protection system supply main. Detects leaks and unauthorised use of water.

Fire sprinkler lines

2

Residential supply lines Residential fire sprinklersystems

DUAL CHECK VALVE BACKFLOW PREVENTER For low hazard cross connections in small pipe sizes. Continuous pressure applications.

Two independent check valves. Checks are removable for testing.

Cross connections where there is a low potential health hazard and moderate flow requirements.

Boilers (small) Residential

Cross connections subject to back pressure or back siphonage where there is a low health hazard. Continuous pressure.

SPECIALITY BACKFLOW PREVENTERS WITH INTERMEDIATE ATMOSPHERIC VENT For low hazard cross connections in small pipe sizes. Continuous pressure applications.

Two independent check valves with intermediate vacuum breaker and relief valve.

Pump outlet to prevent backflow of carbon dioxide gas and carbonated water into the water supply system to beverage machines.

Post-mix carbonated beverage machine

3

Laboratory faucets or pipe lines

LABORATORY FAUCET DOUBLE CHECK VALVE WITH INTERMEDIATE VACUUM BREAKER In small pipe sizes for moderate or low hazard.

Two independent check valves with intermediate vacuum breaker and relief valve.

Cross connections subject to back pressure or back siphonage where there is a low health hazard.

87


88

TYPE & PURPOSE DESCRIPTION INSTALLED AT EXAMPLES

ATMOSPHERIC VACUUM BREAKERS For high hazard cross connections not subject to continuous pressure.

Single float and disc with large atmospheric port.

Cross connections not subject to back pressure or continuous pressure. Install at least 6" above fixture rim. Protection against back siphonage only.

Process tanks Dishwashers Soap dispensers Washing machines

PRESSURE TYPE VACUUM BREALERS For high hazard cross connections. Continuous pressure applications.

Spring loaded single float and disc with independent first check. Supplied with shut-off valves and ball type test cocks.

This valve is designed for installation on pressure potable water supply system 12" above the overflow level of the system being supplied. Protection against back siphonage only.

Laboratory equipment Laundry machines Swimming pools Toilet and urinal facilities 4

HOSE CONNECTION VACUUM BREAKERS For residential and industrial hose supply outlets not subject to continuous pressure.

Single check with atmospheric vacuum breaker vent.

Install directly on hose bibs, service sinks and wall hydrants. Not for continuous pressure.

Hose bibs Service sinks Hydrants

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