Walchem’s Multi-Function Valves (MFV) provide anti-syphon, back pressure, bleed, drain and pressure relief for your 11, 16 and 21 size E class metering pumps. These valves will prevent syphoning when pumping downhill and will increase accuracy and repeatability in applications with little or no system pressure. Pressure relief adds over-pressurization protection in the event of a closed or blocked discharge line. With wetted materials made of PVDF, PTFE and AFlas™, one valve will fit most liquid end options.