Precautions for water pressure test

Water pressure test refers to a testing method that injects medium water into the tested object by

applying specific pressure to evaluate its sealing performance and pressure bearing capacity. This type of

test is mainly used to determine whether there is any leakage in pipelines, containers, or components,

and whether they can withstand the pressure requirements in actual use. When conducting water

pressure testing, there are some key precautions to follow to ensure the accuracy and safety of the test

results.

Test precautions

1.1 Environmental Safety

During testing, it is necessary to ensure the safety of the testing environment, place warning signs such as

“pressure testing in progress” and “no entry”, delineate warning areas, or conduct in a closed state, and

prohibit unrelated personnel from entering the site. For high-pressure and destructive pressure tests, they

should be carried out in dedicated blasting boxes, and operators must have protective measures such as

goggles, gloves, etc. to prevent accidents.

1.2 Selection of Standard Parts

For some test fixtures and connecting parts such as fasteners, blind plates, pipe plugs, valve seats, etc.,

they must be classified and numbered according to the pressure level, and selected correctly according

to the specified test pressure value. When the pressure level is different, only high-pressure components

can be used for low pressure level tests. The practice of using low for high and incomplete fastener

assembly is absolutely not allowed.

1.3 Pressure gauge selection

Choose an appropriate pressure gauge, and the maximum range of the pressure gauge should be 1.5 to 3

times the test pressure, preferably 2 times. The diameter of the pressure gauge dial should generally not

be less than 100mm. For high-pressure products and pressure gauges, the accuracy is usually not less

than 1.6 times the test pressure, and the accuracy is not less than 0.4 level. Pressure gauges with unclear

scales, broken glass, pointer not returning to zero after pressure relief, those that have not been verified

as qualified, and those that have not been sealed with lead are not allowed to be used. If the pointer of

the pressure gauge fails during the test, the pump must be stopped immediately for inspection. When

replacing the pressure gauge, it is necessary to first relieve the pressure or close the valve on the pressure gauge pipeline.

1.4 Test preparation

① During pressure testing assembly, the product must be cleaned of internal impurities and residues,

which may cause additional stress or deformation during the testing process, thereby affecting the

accuracy and reliability of the test results. And all sealing surfaces and fastening bolts on the product

be further inspected: the sealing surfaces should be free of foreign objects and impurities, and the surface

should be smooth. The bolts should have no obvious deformation, thread damage or other abnormal

situations, and the specifications and grades of the bolts used should be uniform.

② Before testing, it is necessary to inspect the entire testing system to ensure the sealing of all

connection parts and ensure that the test can proceed normally.

1.5 Test process

① For water pressure testing, all air inside the specimen should be drained before testing. On the one

hand, it should prevent air from affecting the test results, and on the other hand, it should prevent the

accumulation of air inside the specimen from expanding due to sudden pressure release, which may

cause injury to the operator.

② During the experiment, pressurization should be carried out at the required rate according to the

standard. Jumping pressurization is not allowed, and a uniform pressurization rate should be maintained

to prevent pressure impact from damaging the sample. At the same time, it is necessary to strictly follow

the prescribed testing parameters for operation to avoid abnormal situations such as overpressure and

overheating.

③ During the water pressure test, the deformation of the sample should be observed in a timely manner,

④ After the water pressure test, it is necessary to release the pressure in a timely manner, disassemble the

test piece, inspect the product, and record the test results