Method Statement Title: Installation & Testing of Domestic Water Piping System

Method Statement Title: Installation & Testing of Domestic Water Piping System

1.0       Scope

The scope of this method statement is to detail the method of installation and hydrostatic pressure testing of Domestic Water Piping System.

            Note

            The chlorination and disinfections of the system shall be covered under a separate method statement Ref. ETA/MS/P-016.

2.0       Material

• Copper piping to BSEN 1057 Class X –

• Cold water riser piping from the pumps to the roof tanks.

• Cold water supply piping from the tank to the individual floors upto the PRV station.

• Hot water piping inside the toilets from the water heater to the outlets.

• UPVC piping to BS 3505 class E – Cold water distribution pipes after the PRV.

• Cross-linked Poly-ethylene (PEX) pipes to DIN –16892/16893 – Hot and cold water piping concealed in block wall (wall drops).

3.0       Applicable Location

            Towers, East and West Podiums and Villas.

4.0       Method

4.1       Storage  

4.1.1    The pipes and fittings while unloading shall be slowly lowered, not dropped to the ground.

4.1.2    Timber supports of suitable size shall be placed at equal distance below the pipes. 

4.1.3    Pipes shall be stacked on a flat surface free from any sharp objects and shall be given adequate supports at all times. 

4.1.4    Pipes and fittings shall not be stored under direct sunlight.

4.1.5    While stacking it shall be ensured that pipes of bigger sizes will be placed at the bottom and smaller sizes at top. 

4.1.6    Manufacturers instructions shall be followed, for storage, where applicable. 

                        4.1.7    End caps shall be in place for all pipes until taken out for installation.

            4.2       Installation  

4.2.1    Ensure only approved drawings are used for installation. 

                        4.2.2    Mark the pipe routing on the soffit of slab or as required, duly coordinated with other services and as per approved layout drawings. 

4.2.3    Install hangers and supports with approved material. 

4.2.4    The spacing of the supports for the vertical and horizontal pipes shall be in accordance with the approved details drawings and standards as applicable.

                        4.2.5    The pipes shall be installed at designated levels as per the coordinated layout.

                        4.2.6    The pipes are cut to required length, and all sharp edges and burrs shall be removed.

                        4.2.7    Before jointing, the pipes and fittings shall be checked for defects and the jointing surfaces are cleaned thoroughly.

                        4.2.8    The copper pies shall be jointed by brazing by suitably qualified and skilled tradesmen.

                        4.2.9    Manufacturer’s installation procedure shall be followed as applicable.

• Refer Annexure-I (Soldering of Copper pipes)

• Refer Annexure-II (Brazing of copper pipes)

• Refer Annexure-III (Solvent cement jointing of UPVC pipes)

                        4.2.10  Only manufacturer’s fittings shall be used for jointing, change in direction, change in sizes etc., as required.

                        4.2.11  Expansion couplers / bellows shall be installed in the piping, where it crosses the buildings expansion joints.

4.2.12  The entire piping shall be evenly pitched to achieve 0.2 percent slope towards drain valves.

                        4.2.13  Approved valves shall be installed for all risers and branches as per approved layout drawings.      

                        4.2.14  All valves shall be installed in an easily accessible location and adequate space shall be available for maintenance.

                        4.2.15  PRVs will be installed as per manufacturers instructions at locations approved on layout drawings.

                        4.2.16  All pipe joints shall be left exposed until satisfactory completion of hydrostatic pressure testing.

                        4.2.17  All hot water copper pipes shall be plastic coated.

                        4.2.18  Drain valves shall be installed at all low points.

                        4.2.19  The pipe work, valves etc., shall be identified as per specifications and approved submittals.

            4.3       Jointing Methods

                        Five types of jointing methods will be followed in this project.

                        4.3.1    Copper Pipes

                                    Three types of jointing methods will be carried out for copper pipes.

1. Brazing

Brazing will be carried out for

• cold water risers from pumps to roof tank and

• cold water down take riser pipes 66.7mm to 108mm

by experienced and skilled personnel.

b.         Soldering

                                                Soldering will be carried out for internal hot water piping for washrooms and kitchens.

• Victaulic Grooved Joints

              This method will be used for cold water riser pipe work of 159mm dia only.

                        4.3.2    UPVC Pressure Pipes            

                                    UPVC pressure pipes shall be jointed by solvent cement (Refer Annexure-III)

• PEX Pipes

The vertical dropper pex pipes are connected to the distribution pipes through a male union of approved type.

5.0       Hydrostatic Testing

5.1       Upon completion of installation, the open ended pipes shall suitably be plugged or blanked-off.

5.2       All the joints shall be left uncovered until satisfactory completion of testing.

5.3       Flush the section of the pipe work under test with water.

5.4       Connect a calibrated pressure gauge to the pipe work at a suitable location (Refer Annexure-IV for sample calibration certificate copy).

5.5       Check and ensure all drain valves are closed and in-line valves are open.  

5.6       Fill the section of pipe work under test with clean water. 

5.7       Subject the piping to a static pressure of 350 Kpa above the operating pressure by using a mechanical hand pump.

            5.8       After pressurising the pipe work to the required pressure, a holding time of 2 hours shall be allowed.

            5.9       Inspect all joints, valves, fittings etc. for leaks, if there is a drop in pressure.

            5.10     Repair leaks and defects, if any, with new material as required and retest the pipe work until satisfactory results are obtained.  After rectification, the test pressure shall be maintained for a minimum period of 2 hours.

            5.11     Consultant shall be notified at least 48 hours in advance to witness the test by submission of work inspection request (WIR).

            5.12     Only calibrated pressure gauge shall be used for pressure testing.

6.0       Safety

            6.1       All safety precautions shall be followed as per established project safety procedures.

• Warning sign shall be placed at required location.

• Fire blanket to be kept at the required location.

• Fire extinguisher to be placed at the work spot.

• Hot work permit to be obtained from the concerned safety officer.

7.0       Records

            7.1       Work Inspection request (WIR).

            7.2       Installation checklist duly signed by ETA QA/QC.

            7.3       Test certificate duly signed by NMX and Consultant.

8.0       Attachments

• Test Format

8.2       Annexure-I      Copper pipes Joining (Soldering)

8.3       Annexure-II    Copper pipes joining (Brazing)

8.4       Annexure-III   UPVC pipes joining (Solvent weld)