Buried pipe pressure testing

Thread Content

The water supply pipes need to be backfilled before the hydrostatic test, as both the hydrostatic test and the strength test are destructive tests that involve risks. The main procedure is to first backfill the soil, leaving a gap for the joint; after the hydraulic test is successful, the areas that have not been backfilled are filled in. The water pressure test is a type of permeability test conducted in boreholes. It involves using plugs to isolate a certain length of borehole section, and then applying water pressure to that section; the flow rate under such pressure is measured. The permeability of the rock in that section is determined by the flow rate per unit length under a given pressure, and this method is also commonly used to assess the permeability of rock masses. Note: For pressure pipeline hydrostatic tests, the soil fill must reach 500 mm above the top of the pipes, applicable to water supply, heating, and gas pipelines. Additional information: Method 1, Pre-test phase (1) Gradually increase the water pressure inside the pipeline to the specified test pressure and maintain it for 30 minutes; if the pressure drops during this time, water can be added to restore the pressure, provided that this restored pressure does not exceed the test pressure ； (2) Check for leaks or damage at pipe joints, fittings, etc ； (3) If leakage or damage occurs, the pressure testing should be stopped immediately; the cause should be identified and appropriate measures taken before resuming the testing. 2. During the main testing phase, water injection for pressure supplementation is stopped, and the system is allowed to stabilize for 15 minutes. If the pressure drop after 15 minutes does not exceed the allowable value, the test pressure is increased to the operating pressure, and this pressure is maintained for 30 minutes. An visual inspection is conducted; if no leaks are detected, the hydrostatic test is considered successful.