Maintain constant discharge pressure despite variations in demand or inlet pressure. Eliminates fall off. Easily adjusted for discharge pressures ranging from 50-165 psi. Fully operated by line pressure; no external power source required. Soft seat for drip-tight closure. Easily cleaned, repaired and adjusted without removal from the line. UL listed. ANSI flanged Class 150 or Class 300. Available sizes: 1.5 to 8 inches (globe/angle). Body bonnet is made of ductile iron per ASTM A536, Grade 65-45-12. All internal ferrous surface coated with 4 mils of epoxy.