Fire Protection Pressure Relief Valve Model 2050B-4KG-1, UL/ULC. Listed, Angle pattern, Factory mutual approved, Fast opening to maintain steady line pressure, Accommodates wide range of flow rate, Closes gradually for surge-free operation, Adjustable pressure settings, Not affected by pressure at valve discharge. This valve is designed specially to automatically relieve excess pressure in fire protection pumping systems. Pilot controlled, it maintains constant system pressure at pump discharge within very close limits at demands change. STANDARD MATERIALS: Body & Cover: Ductile iron ASTM A-536, Trim: Bronze seat - Teflon coated - Stainless steel stem - Delrin sleeved, Pilot control system: Cast bronze with stainless steel trim Other optional materials are available upon request. END DETAILS: 150 and 300 ANSI B16.42 PRESSURE RATINGS: Class 175 psi max. OR Class 300 psi max, Water to 180 F max. ADJUSTMENT RANGE: Available in two relief pressure ranges: 20-200 psi (150 class), 100-300 (300 class) Optional: Protective epoxy resin coating of wetted surfaces of main valve cast iron components (UL listed HNFX EX2855)