Check Valve is usually used for stopping back flow of medium.
The maximum permissible leakage of the check valve with non-metal elastic seals is zero, and that of the check valve with meal seals is 0.1xDNmm3/s. Therefore, QC passed valves with metal seals possibly have slight leakage. Hence, in the applications where check valves must not have any leakage, non-return valves with soft seals should be used.
Nominal pressure of Brass Check Valve is 1.6MPa and medium temperature for metal seal is -20℃~150℃, and medium temperature for non-metal seal is -20℃~100℃. When the non-return valve is used for saturated steam, the pressure of the saturated steam should be≤0.6MPa.