Check valves are a type of valve that allows liquids, gases, and steam to flow in only one direction. A check valve can have a 'stopping' mechanism that can be shaped like a ball, disc, piston, or poppet.

What is the main function of check valve?

' The main purpose of a check valve is to prevent backflow in the system. Figure 1 shows an example of a check valve. A check valve relies on a pressure differential to work. They require a higher pressure on the input side of the valve than the output side to open the valve.

When should check valves be used?

A check valve will be used commonly on the discharge of the pump to prevent backflow from the downstream system, when the pump shuts off. Check valves are also used to prevent contaminated media in branches from flowing back into the main trunk line.