General Valve Test Pressure: this standard refers to the international standard ISO5208-2015 Pressure Test of Industrial Valves.

1. Subject and area of application

This standard specifies the requirements, methods and evaluation indexes of pressure test of general valves. It is applicable to the pressure test of Gate Valves, Globe Valves, Check Valves, Plug Valves, Ball Valves, Butterfly Valves, etc.

2. Term

(1) Test pressure

The gauge pressure that the inner chamber of the valve should bear during the test.

(2) Shell test

It is a pressure test of the entire valve shell formed by the valve body and bonnet. The purpose is to test the compactness of the valve body and bonnet and the pressure resistance of the whole shell.

(3) Sealing test

It is a test to check the sealing performance of the sealing pair of the opening and closing parts and valve body.

(4) Upper sealing test

It is a test to check the sealing performance of the sealing pair of the valve stem and valve bonnet.

(5) Duration of test

The duration of the test under the test pressure.

3. Pressure test items

(1) Shell test;

(2) Upper sealing test (This test should be conducted for valves with upper sealing structure);

(3) Sealing test.

4. Test requirements

(1) Pressure test should be conducted for each valve before delivery.

(2) Before the completion of the shell test, it is not allowed to paint the valve or use other anti-leakage coatings, but it is allowed to carry out chemical anti-rust treatment without sealing effect. For inventory valves that have been painted, the coating does not need to be removed if the user requests to redo the pressure test.

(3) Before the sealing test, the oil stain on the sealing surface should be removed, but it is allowed to apply a layer of protective agent with viscosity not greater than kerosene. Valves sealed by grease are allowed to be coated with grease selected according to the design regulations.

(4) During the test, the valve should not be subjected to external forces that may affect the test results.

(5) Unless otherwise specified, the temperature of the test medium should be between 5 ℃ and 40 ℃.

(6) The manufacturer should select the test medium that meets the relevant regulations.

(7) When testing with liquid, we should eliminate the gas in the valve chamber; When testing with gas, we should take safety protection measures.

(8) When conducting sealing and upper sealing tests, we should close it in the way given by the design.

(9) The test pressure should meet the requirements.

(10) The duration of the test should meet the requirements.

5. Test methods and procedures

First, the upper seal test (This test should be conducted for valves with upper sealing structure) and shell test should be carried out, and then the seal test should be carried out.

(1) Upper sealing test (This test should be conducted for valves with upper sealing structure)

Close the inlet and outlet of the valve, loosen the packing gland, keep the valve fully open, close the upper seal, fill the body chamber with test medium, gradually pressurize it to the test pressure, and then check the upper seal performance.

(2) Shell test

Close the inlet and outlet of the valve, compress the packing gland, keep the opening and closing parts partially open, fill the body chamber with test medium, gradually pressurize it to the test pressure, and then check the shell.

(3) Sealing test

Gradually pressurize it to the test pressure, and then check the sealing performance of the sealing pair.

6. Evaluation index

(1) Shell test

During the shell test, there should be no visible leakage at the pressure bearing wall and the connection between the valve body and the bonnet, the shell should be free of structural damage.

(2) Upper sealing test

No visible leakage during the test duration.

(3) Sealing test

As long as it is within the maximum allowable leakage.