Pressure Test Procedures for Water Supply Lines and Dewatering Lines

Test purpose:

To ensure there are no leakages in the fittings.


Test procedure:

  • Ensure that only the fittings are uncovered. Underground pipes should be covered. On the day before the test, it is recommended to fill the pipeline with water at the maximum working pressure.
  • Carefully inspect the pipeline, especially around the fittings, on the day of the test.
  • Important: Cover metal fittings temporarily (branch-off saddles, flanged couplings)
    to prevent the build-up of heat buildup due to sunlight exposure.
  • Test pressures in the table for above-ground installation. Take into account how the pipe temperature might be affected by sunlight exposure.
  • Consider changes in the pipeline's topography, which can create higher local pressures. Reduce the test pressure to adjust for topography.


Pressure testing:

  • Bring the pressure to the test pressure level, then close the feeding line.
  • Expect the line pressure to decrease, since Pexgol pipe is flexible and tends to expand in diameter under pressure.
  • Increase the line pressure again to match the test pressure.
  • The pressure should decrease less with each cycle of pressure reduction and enlargement.

After 3 to 4 cycles, open the valve briefly and close it immediately. Lower the pressure rapidly to approximately 75% of the test pressure by letting water out of the line. Once the valve is closed, the pressure should increase since the pipe has a tendency to decrease its volume. If the pressure does not increase, and decreases instead, investigate the cause (e.g. leakages at the fittings).


Pressure test:

pressure tests table