2-ms. cleaning and flushing of pipework

Masar-MID-Al-Fayhaa/ JV3 -ائتالف المساراألوسط-الفيحاء Boulevard Project / Abdali مشروع البوليفارد / العبدلي

Abdali - Boulevard

TITLE OF METHOD STATEMENT : Cleaning, Flushing and Chemical Treatment

of Hydronic Systems Pipe work

Ref: MS - C10 No 8 Rev 0

Section No. Contents

01 Scope of Work

02 Responsibility

03 Description of Works

04 Labour, Manpower and Plant Requirement

05 Supervision Arrangements

06 Temporary Works To Be Designed And Installed

07 Health and Safety Requirements

08 Attachments

Phone : - (962) 6 5653407 Fax : - (962) 6 5653489 E-mail :- mmf.jv3@g mail . com

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1.0. SCOPE OF WORK

This method statement covers the detailed procedure for flushing and cleaning of hydronic systems pipe work. This procedure defines the method to be used to ensure that the flushing and cleaning of the pipe work used in the hydronic systems, has been carried out as per the contract specification requirements.

2.0 RESPONSIBILITY

2.1 The Construction manager is responsible over all for the implementation of the method statement, to ensure that the team of engineers and foremen and operatives are aware of this method statement and, to ensure that all resources (labour, material and equipment) are available to carry out the work as planned.

2.2 The Senior Representatives of the service providers (Third Party Commissioning Organization and Water Treatment Specialist) are responsible for carrying out the work as per the approved method statement. They are also responsible for ensuring that adequate equipment for mobilization works is in place prior to the starting of work.

2.3 The QA/QC Engineer is responsible for ensuring that the operations have been performed as per the specification, for ensuring that the inspections are done as per Quality Control Procedure and that the Inspections, and the works are offered for approval to the Employer's Commissioning Authority Representative (CxA) and the Engineer as specified.

2.4 The Safety Engineer is responsible for ensuring that all safety precautions are in place, and that all personnel onsite are using the prescribed Personal Protective Equipment (helmet, gloves, safety shoes, coveralls, eye protection etc.). The Safety Engineer must also ensure that all relevant permissions are available for the works.

2.5 With reference to specification sections 01815-1.7.E and 01815-3.3.G the CxA shall review and comment on the plan for carrying out the works covered by this method statement including the testing witnessing and final reports. Recommendations for the testing and witnessing are included in attachment g). CxA shall certify that pipe cleaning, flushing, hydrostatic tests and chemical treatment have been completed.

3.0 DESCRIPTION OF WORKS


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3.1 Objectives

3.1.1 To flush and clean the hydronic systems prior to operation.

3.1.2 To minimize the corrosion in the system metals.

3.1.3 To inhibit the formation of scale and sludge.

3.1.4 To inhibit the growth of microbiological organisms.

3.1.5 To maintain the engineering design and efficiency of the systems.

3.1.6 The objective should be to plan the flushing and chemical cleaning as one continuous process with no

delays between the flushing and chemical cleaning

3.2 Preliminary Works

3.2.1 Ensure that all safety requirements are in place, in accordance with the project safety plan.

3.2.2 Ensure that all Technicians and helpers are aware of the correct materials handling and application

procedures to ensure the best quality of workmanship. Toolbox talks shall be conducted by the works

supervisor, at maximum intervals of every fortnight, to highlight training and special needs for the

subject works

3.2.3 All materials shall be ordered after approval of the relevant drawings and material submittals.

3.3.4 Ensure that the latest revisions of the shop drawings are used for assessment of the water volume

and corresponding chemical quantity to be used.

3.3.5 It is envisaged that the major handling and application of chemicals will take place in and adjacent to

the ETS room at P1 Level. Care shall be taken to protect adjacent works from accidental chemical

spillage by covering by polythene/plastic sheets

3.3.6 On receipt of the material at site store, the same shall be inspected by the Store Keeper / Site

Engineer / QA/QC Engineer, to ensure the materials are delivered, in a good condition and without

damage, and are as per the approved material submittal.

3.3.7 Inspection request (MIR) shall be raised for Engineer’s approval, before transferring the materials to

site for application.

3.3.8 The Site Engineer shall ensure that all necessary access panels have been provided to enable re-


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circulating points, valves and strainers to be reached during the progress of the works. This

requirement applies for example, to the access panel adjacent to each apartment fan coil unit, and

the re-circulating points at the ends of heating and chilled water mains in apartment corridors.

3.3.9 The Site Engineer shall ensure that there are no obstructions to the performance of the cleaning and

flushing operations in the work area.

3.3.10 The Site Engineer shall ensure that all tools and equipment are available as per the scheduled tasks,

and that they are suitable for their intended purpose, and comply with relevant contract requirements.

3.4 Checks to be carried out prior to filling. 3.4.1 Ensure that all equipment is installed in accordance with the manufacturers instructions

3.4.2 Ensure that pump and valve packings and any special valve lubricants are compatible with chemicals

that will be used during the cleaning, flushing and corrosion inhibiting phases of the works.

3.4.3 Ensure that a reliable and adequate source of fresh water is available.

3.4.4 Ensure that energy meters are not installed during the cleaning phase. However isolating valves

and spool pieces should be in place to allow installation of energy meters in the future.

3.4.5Check that probe pockets, pressure gauges, and test points are installed and are accessible.

3.4.6Check that manual and automatic air vents are installed, at high points, and that a method of venting is

provided in any low velocity sections.

3.4.7Check that drain valves and overflows are fitted and are of an appropriate size.

3.4.8Check that connections to heater and cooler batteries are correct in accordance with air and water flow

and that for the initial cleaning phase all the heater batteries, cooler batteries and heat exchangers

are isolated from the systems and that temporary flushing loops are in place.

3.4.9Ensure that all control, double regulating and non return valves are installed in accordance with flow

direction arrows.

3.4.10Ensure that all strainers have the specified mesh and are installed in sections of pipe work which permit

access for isolation, removal and cleaning of the elements.

3.4.11Check that all drain cocks are set in their operational position.


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3.4.12Ensure that access is maintained to all manual valve wheels and to the actuators of automatically

controlled valves.

3.4.13Ensure that there are adequate provisions for introducing chemicals into the systems (dosing pots), and

for drainage of water from the systems during flushing.

3.4.14Ensure that there is an adequate and permanent supply of electrical power for operation of associated

pumps.

3.5 FLUSHING AND CLEANING

3.2.1 The systems will be cleaned in accordance with the following stages:

Static flushing.

Dynamic flushing.

Removal of surface oxides.

Final flushing.

Dosing with corrosion inhibitor and biocide.

3.2.2 Commence with the Static Flushing, in a TOP to BOTTOM sequence by first filling the entire

system with fresh water, ensuring that all air is removed from the pipes, and leaving charged for

48 hours, to soften any inclusions. Subsequently release the water to drain, based on a

predetermined schedule to be agreed with all parties, observing the degree of contaminants and

discoloration of the water during the process. Typically this will be carried out for each building in

alphabetical sequence i.e. A1, A2, A3, A4, B1, B2 etc.

3.2.3 Clean all dirt pockets and strainers, and after replacing, refill and drain the system until the water

being released to drain is relatively clean. This could involve filling and draining the complete

systems at least two more times or as directed by the CxA.

3.2.4 Re-fill the entire systems in readiness to commence Dynamic Flushing.

3.2.5 Install temporary flushing tank, flushing pump and drain valve as indicated in schematic diagram

reference 1.

3.2.6 Commence dynamic flushing with the primary ring main at P1 level, after first confirming that the


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risers in each building are isolated.

3.2.7 With the primary ring main fully primed, turn on the temporary flushing pump. Gradually open the

drain valve until the drain rate balances the mains water flow into the temporary flushing tank. See

attachment f)

3.2.8 Turn on the primary pump and adjust the drain valve until the drain rate balances the mains flow

into the flushing tank. Monitor the pump motor current to ensure that full load current is not

exceeded.

3.2.9 Circulate water around the primary ring for a minimum of 1 hour.

3.2.10 Measure the flow rate in the primary ring to ensure that the required flushing velocity is being

achieved.

3.2.11 Run the pumps until the drain water runs clear.

3.2.12 Stop the pumps and close the drain valve, isolate and clean strainers.

3.2.13 Replace the strainer baskets and repeat the process until the strainer baskets no longer collect

significant amounts of sediment.

3.2.14 Repeat the process gradually introducing the risers and horizontal mains of the upper floors to the

process, in a pre-determined sequence.

3.2.15 If individual circuits or sections of pipe are left isolated for a period of time after flushing, the

soluble iron level of the water will increase, and to bring all parts of the system back within

required limits, the entire system should be flushed again simultaneously.

3.2.16 Sections 3.2.5 to 3.2.15 should be performed separately for the chilled water and heating systems.

3.2.17 Proceed to the Chemical Cleaning phase, within 24 hours of completion of the flushing process.

3.2.18 Fresh cleaning agent (NCE-1as per the attached data sheet) will be introduced to the systems

under the direction of the water treatment supervisor, and circulated for 12 to 16 hours. This stage

of the procedure is intended to remove oil, grease, rust and suspended material from the service

equipment.

3.2.19 Flush the system with fresh water to remove any residue of the cleaning agent NCE-1, and


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dissolved materials.

3.2.20 Introduce the cleaning and passivating product (NCE-6 as per the attached data sheet), to

neutralize the system and to passivate the internal surfaces of the pipes. This stage will take

between 4 and 6 hours.

3.2.21 On completion of the passivation stage the system will be flushed once more with clean water to

remove all remaining traces of chemical cleaning agents, and then completely refilled using fresh

softened water.

3.2.22 The final stage in the process is the adding of corrosion inhibitors and biocides, and at this point

the temporary flushing loops should be removed or isolated so that the FCU's, AHUs heat

exchangers and system pumps are included in the system.

3.2.23 Following the complete filling of the heating and cooling systems with softened water, the final

stage of the process will be commenced, and which entails dosing with Biocides and Corrosion

Inhibitor. In the case of the chilled water system dosing will be with Bionetro 1020 and Biocide

190, and for the heating system Oxyscan 5020 will be used. For the volumes required, and the

target water parameters refer to the information on the attached data sheets.

3.2.24 RSS or an equivalent approved organization as directed by the CxA, will be engaged to carry out

the sample testing outlined in attachments g) and h).

3.2.25 Note: When systems for future retail areas and offices are added, it is important that these

systems are subjected to the same comprehensive cleaning and flushing described above,

before physically connecting to the main distribution networks, to avoid contamination.

4.0 PLANT EQUIPMENT1) Pipe Fitters Tool Box.

2) Water quality test kit.

3) Water meter

4) Temporary flushing tank.


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5) Temporary flushing pump.

Personnel Protective Equipment:

1) Helmets

2) Safety Shoes

3) Coveralls

4) Masks

5) Rubber Chemical Resistant Gloves

6) Safety Glasses

Material Requirement

1) NCE-1 High active multi component cleaner (exact dosage to be determined by water treatment

Supervisor).

2) NCE-6 General purpose de-greasing and passivation product (exact dosage to be determined

by water treatment supervisor).

3) 1175 litres Bionetro 1020.

4) 125 litres Biocide 190.

5) 325 litres Oxyscan 5020

5. SUPERVISION ARRANGEMENTS

The supervision of these works will be under the direct control of the Construction Manager, assisted by the Sector Engineer, Site Engineers and Foremen with the back – up from the Technical Department. All Subcontractor works will be coordinated and controlled by the Construction Manager. A full time

competent Subcontractor Project Supervisor shall be deployed to the site.

6. TEMPORARY WORKS TO BE DESIGNED & INSTALLED Temporary pumps and tanks will be installed and maintained in compliance with required safety standards . See attachment f).


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7. HEALTH AND SAFETY REQUIREMENTS Implementation of Health & Safety mechanisms and checks shall be done as per contract requirements

and the approved safety manual. The safety officer shall carryout the necessary routine inspections. Safety Lighting : Safety lights will be used in case of power failure, ensuring good illumination for the operatives. Task Lighting : Adequate lighting will be provided to ensure good illumination of the working area. Emergency Arrangements : Site general safety procedure will be followed. In case of emergency, the Safety Officer will stop the work and put in to action the emergency arrangements as per the plan. Risk Control : Risk Assessment and their controls are carried out for the following activity / hazards

and enclosed with this method statement.a) Using Hand Toolsb) Ladders and step laddersc) Working at heights.d) Handling chemicals

08. ATTACHMENTS

The following documents are enclosed with this method statement:

a) Risk Assessment Form – Using Hand Tools. b) Risk Assessment Form – Using Ladders & Step Ladders. c) Risk Assessment Form – Working at Heights. d) Risk Assessment Form - Handling Chemicals.e) Data sheets for chemicals to be used during the cleaning, flushing and water

treatment. f) Schematic Diagram for temporary pump and tank.g) Inspection and witnessing recommendations.h) Interpretation of bacterial analysis.


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2-ms. cleaning and flushing of pipework

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