This Cast Iron Wafer Check Valve, Watts 3 IN Model ICV-125-2-2-T, is used in commercial and industrial HVAC applications to prevent water hammer and reverse fluid flow in water lines. It features a cast iron body with aluminum-bronze disc plate, Buna-N seat, PTFE bearings, stainless steel hinge and stop pins, steel plug and eye bolt, and stainless steel springs. The maximum pressure is 200 psi.