Kunkle 537 Safety Relief Valve — 2″ x 2-1/2″ FNPT, 15-160 PSIG (Hot Water ASME Section IV)

The Kunkle 537 is a safety relief valve for low pressure hot water boilers, heat exchangers and generators. It serves a dual purpose: relieving the overpressure created by thermal expansion under normal firing conditions, and the overpressure in the form of water or steam created by over-firing when electrical or other controls fail. Construction is extra heavy for long life, with a top guided disc assembly carrying a resilient seal in the seating area, an isolating diaphragm that protects the working parts from corrosion caused by discharged liquid, a pivot between disc and spring that corrects misalignment and compensates for spring side thrust, and a heavy duty lift lever. This 2″ x 2-1/2″ FNPT variant has an orifice area of 3.142 in² and relieves 4,069 to 24,871 lb/h (4,069,144 to 24,871,338 BTU/h) at 15 to 160 psig. Set pressure range is 15 to 160 PSIG (1.0 to 11 barg) over a temperature range of -20°F to 250°F (-29°C to 121°C). The 2″ size has a cast iron A126 Class A or B body; note that the 3/4″ and 1″ sizes are bronze. ASME Section IV and Section XIII code service with the ‘HV’ designator, National Board certified. Specify your required set pressure when requesting a quote.

↓ Kunkle 537 Datasheet (PDF)