This leakage level, Qiao Zhun, clearly stipulates the pressure and temperature range for inspecting the valve leakage. It is difficult and inappropriate to try to raise these parameters to higher pressure and temperature, because the accessible L cracks at the sealing surface of the valve core or the valve seat and errors in the valve assembly can be found in this level of leakage test.
Class V is mainly applicable to regulating valves with additional special sealed balanced or unbalanced single metal seats and single channel. Different from other grades, the allowable leakage of Grade V depends not only on the valve diameter, but also on the maximum differential pressure when the valve is closed under actual conditions. The test medium of Grade V is 50~125T (10~52 "C) water, and the test pressure is the maximum working differential pressure passing through the valve core, but not more than the ANSI valve body pressure grade. The minimum value is 100psi (0.7MPa) During the test, it should be noted that the whole valve chamber and connecting pipe must be filled with water and the valve core must be closed before the valve can be pressurized. The thrust shall be adjusted to the maximum rated value, which shall not be exceeded. In addition, sufficient time shall be allowed for leakage medium to flow into the pressurizer. Level V allowable leakage is 5 10ml ／ min in psi (5 10m/s mm MPa)

Pneumatic butterfly valve is a kind of pneumatic valve and pneumatic control valve. Pneumatic butterfly valve is mainly connected by: flange type and wafer type; The sealing forms of pneumatic butterfly valve mainly include rubber seal and metal seal. The pneumatic butterfly valve controls the switch of the butterfly valve through the power signal. This product can be used as the shut-off valve, control valve and check valve of the pipeline system. With manual control device, once power failure occurs, it can be operated manually temporarily without affecting the use.