Provisions on airtightness testing in GB150
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I have a question for the experts here: the leakage tests mentioned in the new version of GB150.4-2024 include airtightness testing, ammonia leak detection testing, halogen leak detection testing, and helium leak detection testing. The other requirements specified in the airtightness test shall comply with NB/T 47013.8. NB/T 47013.8 mentions the bubble test, but it does not specify what the corresponding test pressure should be; GB150 states that it should be the same as the design pressure. What is included in ASME Volume V is also the bubble test. Can GB150 also change \"airtight\" to \"bubble\"? Upon closer inspection, there isn’t actually much difference.
It should be a continuation of the industry’s historical* practices...
The airtightness test mentioned in GB150.4-2024 is a leakage detection method aimed at verifying the sealing performance of pressure vessels at their design pressure. In accordance with the requirements of GB150 and NB/T 47013.8, the airtightness test can be carried out using the bubble test. The bubble test is a common testing method that determines the presence of leaks by observing whether bubbles form under test pressure. Even though GB150 uses the term “air-tightness test,” the actual procedure carried out is the same as that of the bubble test; therefore, it can be considered that the two are equivalent. As for the test pressure, it shall be in accordance with the design pressure specified in GB150. .
The other requirements specified in the airtightness test shall comply with NB/T 47013.8. Meanwhile, NB/T 47013.8 mentions the bubble test – firstly, the bubble test is merely one type of leakage or airtightness test; the standard states that this also includes the ammonia, helium, and halogen leak detection methods mentioned in 150.
What type of pressure vessels require a hot gas cycle test
There are not only the bubble method but also the colorimetric method for airtightness testing
NB/T47013.8-2012, Appendices A and B: Bubble leak detection ≠ GB/T150.4-2024, 11.5.3: Airtightness test. Airtightness testing is the most commonly used leakage test, as well as the least costly one. The requirements for airtightness testing shall comply with the relevant provisions in TSG 21-2016; GB/T150-2024 is merely consistent with TSG 21-2016. The other requirements regarding airtightness testing in GB150-2024 refer only to the general provisions; they are not what you understand by bubble leak detection. Just because there are many similarities does not mean that they are the same thing.
Bubble leak detection is not a mandatory leak test; it is illegal to use bubble leak detection unless specified in the design documents or as a result of changes to the technical specifications.