RK and RKE non-return valves are used to prevent the return flow of fluid in pipes. Only RKE non-return valves may be used as end valves (e.g. vacuum breakers). This equipment has passed the appropriate tests and bears the relevant markings, and must not be used with safety-relevant functions (e.g. safety valves). RKE non-return valves are only available with a metal valve disk. Wafer-type non-return (check) valves for sandwiching between flanges, designed with closing spring for installation in any position. Without spring only for vertical lines with upward flow. Self-centring valve body. Suitable for liquid, gas and steam. Please note the classification according to the Pressure Equipment Directive (PED).