This 1" boiler pressure relief valve is used in hot water space heating boiler applications to protect against excessive pressure on all types of hot water space heating boiler equipment. It consists of an iron body construction with expanded outlet drain connections for hot water space heating boilers, non-metallic disc-to-metal seating, stainless steel spring, and test lever. Series 740 offers large discharge capacity, resists corrosive water conditions, resists sticking and freezing, and prevents water and sediment from being trapped in the seat. It is designed for emergency safety relief, not as an operating control. The pressure relief is set at 65 psi ( 448.1 kPa) with corresponding high pressure ratings up to 2,349,000 BTU/hr.

• Water seal of high temperature resisting material isolates spring working parts from water during relief
• Non-mechanical seat-to-disc alignment will not stick or freeze
• Water can not be trapped and sediment can not foul seat
• Iron body with expanded outlets for hot water space heating boilers