Totally there are several valve tests that need to be done throughout the production process. From design, manufacturing, installation, and operation to the maintenance, in every step, there’s always a valve test. And the most important tests are usually conducted before the valve leaves the factory.
1. Types of Valve Tests
Generally, there’re mainly two types of valve tests: Hydrostatic Test and Pneumatic Test. In the case of the hydrostatic test, the medium to use is liquid; in the case of the pneumatic test, the medium to use is gas. Generally speaking, the potential energy of compressed gas is much greater than that for a non-compressible liquid.
According to the purpose of the test, the valve tests can be classified into two types: strength test and sealing test. Normally both the strength test and the sealing test are conducted on the hydraulic test bench unless there’s a higher operating pressure standard and the test will be pneumatic.
2. Sampling Rate
To guarantee the quality of valves, there’s a sampling rate for different kinds of valves: 20% of low-pressure valves must be tested randomly; and in the case of medium and high-pressure valves, 100% should be checked.
In this article, we mainly focus on the sealing test for its the most common and important test
3 Sealing Test
In the case of the gate valve, the standard sealing test procedure is the following:
- Open the gate plate.
- Allow the pressure inside the valve to rise to the specified test value.
- Close the gate plate.
- Immediately remove the gate valve to check for leakage on both sides of the gate plate sealing. If you find any leakage, immediately replace the valve with a new one.
- Open the butterfly plate and close the other end
- Inject the test medium at the pressure specifier by testing requirements.
- Close the butterfly plate
- Check for leakage on both sides to see whether there’s leakage.
As a professional valve producer, Lituo conducts every valve test strictly according to the standard process. For we’ve always been dedicated to offering valves of high quality.
For more details: https://www.watersvalve.com/products/