Fire Hydrant Pressure Reducing Valve Model 790-63 for fire hydrant service & Model 790-67 for high pressure fire hydrant service. This valve is a hydraulically operated, pilot actuated automatic control valve for pressure reducing service. The valve will control pressure right down to shutoff. The valve is used to lower pipeline pressure to a predetermined set point. The valve automatically controls downstream pressure, from NO flow to full open flow, without regard to changes in the inlet pressure. Outlet pressure control is smooth and precise since the friction and hysteresis of the valve and pilot is negligible. PERFORMANCE SPECIFICATIONS: Cf factor: 0.9, Rangeability: 500:1, Bearing friction: No friction from slip-type bearings STANDARD MATERIAL: Body 18-8 stainless steel, Liner: Natural rubber 65 durometer, Liner retainer: 18-8 stainless steel PILOT: Body: ASTM B62 bronze, Spring cover: ASTM B62 bronze, Wetted parts: Bronze & Buna-N ACCESSORIES: Shut-off cock: Brass, "Y" strainer: Bronze, Speed controls: Brass, Control fittings: Brass END DETAILS: Inlet: Female American National Fire Hose Connection (Section Thread NFPA-194-1974) - Outlet: Male American National Fire Hose Connection (Section Thread NFPA-194-1974), OPERATING PRESSURE: Determined by components as high as 720 psi max., MAXIMUM DIFFERENTIAL: 150 psid continuous - 225 psi intermittent, TEMPERATURE RANGE: 32 to 185 deg. F