method statement for laboratory compressed air and vacuum system

The National Co. For Mechanical & Electrical Works

Method Statement for Laboratory Compressed Air and Vacuum System

The American University in Cairo New Campus Development

Egypt National For Mechanical & Electrical Rev: 0Date : 12-July- 2006

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Contents

1. PREAMBLE

2. INTRODUCTION

3. HEALTH AND SAFETY

4. DEFINITIONS

5. SPECIFICATIONS CLAUSES

6. REFERENCES / CODE OF PRACTICES

7. INSTALLATION PROCEDURES

7.1 EQUIPMENT

7.2 DELIVERY, STORAGE AND HANDLING

7.3 INSTALLATION PREPARATION

8. FLUSHING

9. PRESSURE TESTS


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1. Preamble :

This procedure defines the method used to ensure that the Laboratory Compressed air and Vacuum piping system installation comprising all pipes, tubes, valves, fittings, reducers, expanders, nipples, vents, anchors, brackets, sleeves and all accessories, components connected thereto as an integrated part of the Laboratory Compressed air and Vacuum piping system to be correct and acceptable and conform to the contract documents, drawings and the general specifications. The preface explanation of the proposed stages statements for the Laboratory Compressed air and Vacuum piping system installation works would briefly clarify our understanding of the services to be provided for the AUC New Campus Development project as well as our understanding of site conditions and logistic, thereto stages of construction to be adapted in our work. Stages of site installation of pre-fabricated and site fabricated

piping for different systems to be adapted to our work shall comply with the general conditions

and specifications of the contract, yet the following aspects must be highlighted as an

important factor for the installation work.

- The importance of the safety to this project.- The importance of meeting project milestone dates. - The importance of the final product quality.

2. Introduction :

The procedure for piping works installation includes the following steps:

- Define responsible personnel.- Obtain PMCM permit to work.- Create a safe access to the areas where piping installation

works are to be done.- Preparation works to establish safe "confined spaces ".- Test commission and handover the work.

3. Health and Safety :

This section covers the safety precaution procedure, containing the following

Points:


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- Lifting, welding and all installation equipment and tools shall be in safe and good working conditions, damaged cables & power cables shall be replaced.Welders shall wear the following:-

- Leather jackets.- Cap sleeves or aprons.- Welder's helmet.- Leather protection gloves. - Safety shoes.- (Samples shall be submitted to PMCM, HSE manager for

approval). - Grinding workers shall wear face shields in addition to the PPE

when grinding.- Painters shall wear masks when painting, sandblasting

operators shall wear respirators when sandblasting. - All personnel in the working area shall wear, as a minimum,

safety shoes, safety helmets and protective glasses.- Prior to hot work activities a "hot work permit "(SSJV HSE

program-attachment) shall be filled-in and approved by SS JV HSE Department.

- Safety precaution signs shall be provided in the working area. - Working area shall be clean, free of oil, grease and obstacles,

and surrounded by warning tapes, House keeping shall be fully enforced.

- All material shall be stored in a secure , safe area. - Fire extinguishers shall be available with the working groups

during the work. - Rolling scaffolding shall be safe and in a good position to allow

performing the work in a safe manner, only green tagged scaffolding to be used, working on red tagged scaffoldings shall be forbidden.

- A first aid box must be available with each work group. - SSJV emergency facilities shall be used in case of emergency. - Potable water must be available at the work area.

4. Definitions :

- ASME American Society of Mechanical Engineers

- AWS American Welding Society- HVAC Heating , Ventilation and Air

Conditioning - SMAW Shield Metal Arc Welding - PPE Personnel Protective Equipment- DFT Dry Film Thickness- NDT Non Destructive Testing


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- RT Radiographic Test

5. Specification Clauses :

- Specification section: - Div. 15010 General provisions for mechanical work.- Div. 15055 Painting.- Div. 15060 Piping Specialties.- Div. 15100 Valves.- Div. 15410 Plumbing Piping and Fitting Material- Div. 15990 Test and Balancing.- Div. 15481 Laboratory Compressed air and Vacuum piping Pumps.

6. References / Code of practices :

- The piping installation activities shall be carried out in accordance with the international codes, standards and the client specifications stipulated in the contract documents:

- ASME IX (Welding, brazing and Welders, braziers Qualification Code).

- ASME 31.1 (Pressure Piping Code).- ASTM (American Society for Testing and Materials). - ANSI ( American National Standards Institute ).

7. Installation Procedures :

7.1. Equipment : - Installation equipment will be as follow:

-Pipe Cutting/Threading Machine for Mechanical Fittings.-Welding Machines. -Grinding and Drilling Machines.-Welding Electrode Oven.-Rolling Scaffolds.-Hand Tools.

7.2. Delivery, Storage And Handling:

- Material deliveries to the site shall be in such intervals to ensure uninterrupted progress of work.

- Materials shall be stored to permit easy access for inspection and identification. Pipes shall be kept off ground, using pallet, platform or other supports. Pipes and packaged materials shall be protected from corrosion and deterioration.


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- Material shall not rest on pipes in a manner that might cause distortion or damage to member or other pipes.

- Storage area must be well ventilated.- Material inspection requests (MIR's) (attached) shall be submitted

at the time material arrives at site. 7.3. Installation Preparation :

- Mechanical supervisor will instruct the tradesmen regarding the execution of the works and will distribute all necessary approved, latest revision construction drawings.

- The supervisor will also check that tools and equipment available are in compliance with the contract requirements.

- All materials and documentation relevant to a particular section of works will be checked by the construction department prior to the commencement of work, ensuring that these are of the correct type as reviewed by the consultant.

- Before commencement of any construction works, pre-inspection will be carried out on all materials prior to it's leaving the storage area. The consultants will be invited to attend this inspection at their discretion.

- Prior to the commencement of any construction works, areas and access will be inspected to confirm that they are in a suitable condition for construction works

to commence.

7.4. Jointing Methods: 7.4.1.Screw Joints for black steel pipes diam. 1",1 ¼ ",1 ½ "&2"

1. Full cut threads shall be used as shown below:

Nominal Pipe Size(mm) Threads/c

m

Bore Size(mm)

Thread Length

(mm)

Thread Depth

(mm)

25 4.5 28.97 17 17.46

32 4.5 38.1 18 17.46


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40 4.5 43.66 18.5 17.46

50 4.5 55.56 19.5 19.05- Pipes ends shall be cut square, debarred and cleaned.- Male thread shall be sealed with Teflon tape.- Care shall be taken when handling threaded piping.

7.5. Method of Installation: 7.5.1. General:

- The installation shall be executed in accordance with the manufacturers instructions.

- The drawings shall indicate the size and location of piping. - Piping shall meet field conditions and coordination between

trades.- All changes in direction of piping shall be made with fittings.

For the compressed air system, tees will be installed instead of elbows, the open end will be plugged.

- The compressed air system shall be installed to drain at low points. Valves will be fitted to drain any condensate.

- Take-off to outlets shall branch off from top of main and shall be equipped with a shut off valve

- All piping connections to equipment shall be made with offsets provided with approved screwed or welded fittings, bolted and gasketed flanges or screwed unions, ensuring that the equipment can be serviced or removed without dismantling the piping.

- The drawings shall indicate the size and location of pipe.- Pipes shall be installed in straight and parallel lines.- Concentric reducing fitting shall be used to reduce pipe

diameters from size to size.- Anchor all pipes to compensate for expansion and contraction

shall be installed in such way to prevent excessive strains on piping as per approved shop drawings details.

- Flexible connection joints at building expansion joints to be provided and approved from consultant.

- Anchor and guide all piping to compensate for expansion and contraction shall be installed is such way to prevent undue strains on piping or apparatus

8. Flushing:


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- Before testing, the compressed air and Vacuum pipe systems shall be cleaned from debris, dirt, grease and foreign material.

- The flushing will be carried out with compressed air, starting from the small size branches, blowing towards the larger pipes at the equipment room. The procedure will be repeated until the whole systems are clean.

9. Pressure Tests: - Compressed air and Vacuum system.

Initial pressure test.♦ Before connecting the piping system to the compressor

unit, the piping system shall be subject to a test pressure of 1.5 times the working pressure (minimum 150psi) with oil free, dry nitrogen or compressed air. This test pressure shall be maintained unit each joint has been examined for leakage by means of soapy water. Leaks, if any, shall be located and repaired.

Standing pressure test. ♦ After the initial pressure test is successfully completed,

the piping system shall be subject to a 24hour standing pressure test at 20% above the normal operating pressure. After the system is filled with oil free nitrogen or compressed air, the source shut-off valve shall remain leak free for 24 hours. be closed and the test compressor removed. The only allowable pressure change during the 24 hour test period shall be those caused by variations in the ambient temperature around the piping system.

♦ Leaks, if any, shall be located and the test repeated.Note: The Vacuum gauges will not be installed during the

above mentioned tests, but for the operational test of the system the system only.


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method statement for laboratory compressed air and vacuum system

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