This stainless steel high pressure check valve allows only single direction flow. It has a stainless steel body with viton O-ring so it is suitable for in line applications with not only water but with most chemicals.
A check valve or non-return valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction..
Check valves are two-port valves, meaning they have two openings in the body, one for fluid to enter and the other for fluid to leave. There are various types of check valves used in a wide variety of applications. Check valves work automatically and most are not controlled by a person or any external control; accordingly, most do not have any valve handle or stem.
An important concept in check valves is the cracking pressure which is the minimum differential upstream pressure between inlet and outlet at which the valve will operate. Typically the check valve is designed for and can therefore be specified for a specific cracking pressure.