Relia Valve is a check valve manufacturer, supplying types of check valves such as swing check valves, piston check valves, and double disc check valves with respect to API 6D, BS 1868, and API 594.
A check valve is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. Check valves operate automatically and are typically not controlled by a person or any external control; as a result, most do not have valve handles.
An important concept in check valves is the cracking pressure, which is the minimum differential upstream pressure between the 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.