This check valve is one of the quite important valves. This valve allows the material to flow in only one direction. Meaning that this valve will allow the pressure to flow from one direction and if the pressure returns from the same line, then it stops it.
And does not allow the pressure to flow back and forth. Check valves are used in many places. Most check valves will be located on the outlet side of the pump. With the help of these valves, the pump is protected from backflow.