The disc break
The cause of the disc breaking is:
Check valve before and after the medium pressure is close to balance and each other "saw" state, disc often flapping with the valve seat, some brittle materials (such as cast iron, brass, etc.) made of disc is broken.
The prevention method is to use the disc for the toughness of the check valve.
Medium backflow
The reasons for the reverse flow of the medium are:
(1) sealing surface damage; ② clip in impurities.
Reverse flow can be prevented by repairing the sealing surface and cleaning impurities.