Common use of Leak test Clause in Contracts

Leak test. This test applies to one unit that has not undergone previous design qualification tests and additional units as specified in other tests in Annex4, paragraph 2. The leak test is performed at ambient, high and low temperatures. The unit shall be thermally conditioned at each of the required test temperatures and held pressurized to ≥ 2 MPa for at least one hour to ensure thermal stability before testing. The outlet opening is plugged with the appropriate mating connection and pressurized leak test gas is applied to the inlet. The required test conditions are: (a) Ambient temperature: condition the unit at 20 ± 5 °C; test at 2 ± 0.5 MPa and ≥ 125 per cent NWP; (b) High temperature: condition the unit at ≥ 85 °C; test at 2 ± 0.5 MPa and ≥ 125 per cent NWP; (c) Low temperature: condition the unit at ≤ -40 °C; test at 2 ± 0.5 MPa and ≥ 100 per cent NWP. Following conditioning at each of the specified test temperatures, the unit is observed for leakage while immersed in a temperature-controlled fluid (or equivalent method) for at least one minute at each of the test pressures listed above. If no bubbles are observed for the specified time period, the sample passes the test. If bubbles are detected, the leak rate is measured by an appropriate method. The leak rate shall not exceed 10 Nml/h of hydrogen gas.