What is Non Return Valve | Check Valve | Construction, Working

The valve which allows flow of oil in only one direction and block the reverse flow of oil, is known as check valve or Non Return Valve.

Construction

1) Poppet with spring : The movable member is the poppet/ball placed with the help of spring.
2) Valve body : It is provided with ports and accommodates the poppet with spring.
3) Inlet and Outlet port :The inlet port P is provided for entry of oil and outlet port A for discharge of oil.

Working

It work on two mode

A) No flow

• It is functionally a one way traffic control sign which is obtained by no flow position.

• When fluid attempts reverse direction of flow from port A to port P, the spring hold the poppet at the valve seat at port P and block the oil path, hence oil can not flow from port A to port P.

B) Free flow