Fire Hydrant Pressure Relief Valve Model 750-60 This valve will open when inlet pressure begins to exceed the preset pressure and will allow enough flow to maintain that inlet pressure. The valve will modulate to exhaust line pressure to keep it below the set point maximum. The set point is adjustable over the entire pilot spring range. The valve will control from no flow to full open flow without any chattering or slamming under low flow conditions. There is no slip-type friction because the main valve has no bearings. 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, Control piping: Copper, 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