Hydrostatic Pressure Test

Those types of polymer pipes and connections such as polyethylene and polypropylene or PVC pipes in which fluids or water will pass through them with pressure, an important and vital test called resistance to hydrostatic pressure will be performed on them.

Failure to pay attention to the hydrostatic test in pipes or the resistance of pipes to hydrostatic pressure can lead to many injuries. Suppose a pipe is manufactured according to the specifications and is used at the maximum operating pressure, but the failure to perform the hydrostatic pressure test or a mistake in performing it has caused it to leak and burst after a period of use in the soil or buildings. has been A lot of money has to be spent to compensate for the damage caused. Therefore, by conducting hydrostatic pressure test in pipes and fittings, financial and even life damages can be avoided.

Hydrostatic pressure test of PE-X pipes

In the pipe hydrostatic pressure test, the pipe or connection is exposed to internal hydrostatic pressure at a certain temperature at a constant value for a certain period of time. This hydrostatic pressure is provided by water at a certain temperature.

In PE-X/Al/PE-X composite pipes, the size of each layer (diameter and thickness) and mechanical properties (modulus of elasticity and Poisson’s ratio) play the main role in the long-term hydrostatic pressure tolerance of the pipe. Also, the type of weld, the quality and grade of the aluminum layer effectively affect the long-term hydrostatic pressure of the pipe.

For M-type composite pipes (aluminum with PE-X or PE-RT inner layer, the control points of the hydrostatic pressure test for pipes with a reference curve should be extracted from the reference curve, and the test for pipes without a reference curve that has a usage category of 5 and working pressure There are 10 times, it should be done according to the table below.

The test method is according to the national standard of Iran No. 16376. The free length of the test piece must be at least 10 times the external diameter, so that it is not smaller than 250 mm. When the test is done in a water bath, it needs 2 hours and when it is done in an air oven, it needs 4 hours of isothermal. During the test and after that, the pipes should not suffer from bursting, delamination and leakage.