Leak testing high pressure valves

摘要

Testing the leakage rate of a high pressure valve of the type used in natural gas pipelines or in filling station pumps, for example, is a challenging task. To assure that no hydrogen can escape from the valve, it has to have a very low leakage rate of not more than 1.0 × 10~(-6) mbar l/sec. This assures, for example, that no viruses can escape from the valve due to leakage. (By comparison: These leakage rate ranges differ very significantly from the leakage rates that enable a bubble of air escaping under water to be seen. The maximum "bubble visibility limit" in water is in the range of ～ 10~(-3) mbar l/sec.)