Liquid strike When a liquid strike can be heard inside the compressor to send metal impact sound, and may be accompanied by a severe vibration of the compressor. The hydraulic strike causes the valve to rupture, the compression head washer's damage, the connecting Rod's breakage, the machine shaft's breakage as well as other type of compressor's damage. When the liquid refrigerant migrates into the crankcase, the liquid-hit phenomenon will occur when it is powered on. In some units, due to the relationship between the pipe structure or the location of the parts, liquid refrigerant will accumulate in the suction pipe or evaporator during the unit shutdown, and will be in the form of pure liquid and enter the compressor at a particularly high speed when the machine is powered on. The speed and inertia of the hydraulic strike are enough to damage the protection of any internal compressor anti hydraulic strike device.