Unique Model 100E VFD and 100ES VFD valves are designed to minimize flow losses and hydraulic shocks in the pumping system. New 1" sized pump check valve for use with variable-frequency drive controlled submersible pumps won’t “chatter” and become noisy when the VFD goes to low-flow conditions. Eliminates noise, premature wear, and eventual failure. The inlet and outlet threaded areas allow for longer pipe threads. An exclusive guided poppet system (optional SS poppet), ensures that the valve automatically adjusts noiselessly from high to very low flow rates. Unleaded bronze valve body incorporates corrosion-resistant internal parts that have a durable high-strength design. Can be installed in horizontal or vertical piping installations. The physical valve dimension and pressure rating are the same as for the popular Model 100LE.