Application : Like a one- way spring valve, it is a valve which the fluid can pass through in one direction and it prevents the return of the flow. This faucet works with fluid pressure and has no other controlling device on its exterior body. The faucet opens through the flow pressure which is applied to the surface of the valve and it closes when the flow stops and the spring on the back of the valve applies pressure to it. Places to be installed : Submersible Water Pumps Well- Pumps Urban Water Supply Networks Building Heating Facilities Compressed Air Systems Pneumatic in order to prevent tiny particles, dust, and sand from entering highly sensitive systems Warranty : 5 Years National Standard : PN25