What happens when a check valve fails?

Update:25-06-2021
Summary:Failed check valves are fun. Not really. Failed check valve  Check Valves Manufacturers in China often have catastrophic...
Failed check valves are fun. Not really. Failed check valve  Check Valves Manufacturers in China often have catastrophic consequences for the machine. I don’t have pictures but have seen several machines destroyed. In example CV failed to close on feed water pump for auxiliary boiler. The pump sped backwards, the winding came out from the rotor of the electric motor because of overspeeding. The bearing housing were ripped off and everything inside of the motor was chewed to pieces. It was very loud and dramatic event. Or small refrigeration compressor tripped, CV failed and it went to reverse spin it sounded like a mosquito for few minutes. We don’t know how high the speed went because all speed measurements were overrange. Surprisingly the machine survived.