Is it possible to conduct a airtightness test after the pressure test has been passed?
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This post was last edited by SDHZZXM on 2017-3-29 at 15:59. As the title suggests: For pressure vessels, is it possible to conduct a airtightness test after the pressure test has been passed? Under what circumstances should this be done?
If the pressure test is successful and there are no operations such as disassembly, then a leak test is not necessary. It is explained in 50316.
This post was last edited by SDHZZXM on 2017-3-17 at 16:29. Which one in 50316 provides an explanation? What about pressure vessels?
Pressure testing must first comply with the provisions in the design documents; if pressure testing is specified, the design documents should indicate whether a leak test is also required.
For pressure testing, air is generally used as the testing medium. If the material contained within the container has high permeability, then a leak detection test is necessary, such as ammonia leak detection, halogen leak detection, or helium leak detection (in which case it is pointless to conduct a airtightness test using the same medium as in the pressure test)
Unless it is to conduct a gas-tightness test after the user installs the safety valve and other instruments.
The pressure test is a strength test in which the pressure is maintained for a short period of time (usually about ten minutes) at the test pressure, in order to assess the overall strength of the equipment. A gas-tightness test is a test to determine the tightness of equipment; it is conducted at the design pressure of the equipment to assess its sealing quality. Generally, this test needs to be carried out for a sufficient length of time, depending on the permeability of the medium used. The short duration of a pressure test cannot replace the long-duration requirement of a leak test; therefore, a pressure test cannot substitute for a leak test.
If it passes the airtightness test requirements, there’s no need to do it!
Short-term and long-term requirements. There shouldn’t be much difference between the two tests...
The pressure test evaluates the overall strength of the equipment itself; no additional components such as safety accessories are required for conducting this test； The airtightness test evaluates the tightness of the equipment during operation; it is necessary to equip the device with all necessary safety accessories before conducting the test. Additionally, depending on the permeability of the medium used, the pressure must be maintained at a constant level for a sufficient length of time, usually at least 30 minutes. Therefore, it is possible to conduct a airtightness test after the pressure test has been passed.