Currently I’m working under a 600mm pipe laying project in Middle East. We had finished the pipe laying work and now come to the final stage of the work.
Previously we have done and passed the 1st pressure test along the pipe laying sections. As per requested by the authority, we need to complete another pressure test (9 Bars) by testing the whole pipe length before we can divert the water supply to the new laid pipe.
We have tuned the pressure to 9 bars and maintained for 24 hours. However the pressure was dropped to 7 bars and extra 400 liters of water was pump into the water pipe. The pressure test was failed but we could not locate any leakage along the pipeline.
Information for my pipeline:
Pipe Diameter : 600mm Ductile Iron Pipe
Pipe Length : 1500m
Pressure : 9 Bars
Allowable water tolerance : 180 liter/km/24hrs
Highest Elevation : 41.225m
Lowest Elevation : 34.384m
Pressure Gauge : 37.781m (End of pipeline)
Valve Chamber : 2 nos. Air Valve, 2 nos. Washout Valve, 2 nos. Butterfly Valve
My subcontractor had fixed the pressure gauge at the end point of the pipe instead of the lowest point. Thus I’m seeking help here since this is the first pipe laying project for me. Kindly provide me any advice or guidelines before I redo or conduct the pressure test.
For the second pressure test, the specification is almost the same except,
Pipe Length : 19000m (approx.)
Highest Elevation : 49.368m
Lowest Elevation : 30.749m
Valve Chamber : Total 42 nos. 15 nos Air Valve, 16 nos Wash Out Valve, 11 nos Butterfly Valve.
Thanks for your time and help.