Increased system output with total valve tightness to 96 percent of set pressure without leakage. All plastic pilot seats and seals provide chemical compatibility with corrosion inhibitors in feedwater service. Balanced design ensures proper valve operation and lift unaffected by back pressure; pilot exhausts to main valve outlet with no effect on set pressure. Reduced product loss and pollution through soft seats for premium tightness before and after relief cycles. Modulating action minimizes flow and resultant noise during normal system upset, reducing noise abatement costs. Non-flowing pilot reduces seat wear and minimizes entrance of dirt and particulates. Easy, single set pressure adjustment is accurate and dependable. ASME Section I stamp for steam and water service; ASME Section VIII and Section XIII for steam also available. Rugged bracket pilot mounting protects against vibration and careless handling.