1. High-purity bulk gas pipelines should be tested by leak detection method, inward leak detection method, valve seat leak detection method and outward leak detection method.
2. The inward leak detection method (sneeze method) should use the method of vacuuming inside the high-purity gases pipeline and externally spraying the helium gas to detect the leak.
3. The valve seat leak detection method should use the upstream of the valve to fill the helium gas and the downstream vacuum method to detect the leak.
4, the outward leak detection method (sniffer method) should be used in the high-purity gases pipeline filled with helium gas or helium-nitrogen mixture gases, the external use of a sniffer to check for possible leaks to detect leaks.
5, nitrogen leak detection instrument should use mass spectrometer nitrogen detector, its detection accuracy should not be less than 1
6. The leakage rate of high purity gases helium leak detection should meet the following requirements:
6.1. The leak rate measured by the inward leak detection method shall not exceed 1*10-9 mbar. l/s;
6.2, the leakage rate measured by the valve seat leak detection method shall not be greater than 1*10-6 mbar. l/s;
6.3. The leakage rate measured by the outward leak detection method shall not exceed 1*10-6 mbar. l/s
7. After the leak detected by the leak detection, the leak test should be re-tested and qualified, and then the leak should be checked again according to the regulations.
8. All possible points of leakage should be separated by plastic bags.
9. After the system test is completed, it should be filled with high-purity nitrogen or argon gas and should be purged.
10. After the test is completed, a test report should be submitted.www.wxytgas.com