Model 537


Bronze for 3/4-inch and 1-inch inlet models, Cast iron for 1-1/2-inch and 2-inch inlet models.


  •  Extra heavy construction provides long life.
  • Top guided disc assembly incorporates resilient seal in seating area.
  • An isolating diaphragm protects working parts from corrosion caused by discharged liquid.
  • Pivot between disc and spring corrects for misalignment and compensates for spring side thrust.
  • These safety relief valves serve the dual purpose of relieving (1) over pressure created by thermal expansion under normal ’on and off’ firing conditions and (2) over pressure in the form of water or steam created in over-firing due to failure of electrical or other controls.

Model 537

Pressure Limit:15 to 160 psig
Temperature Limit:-20° to 250°F
4 Sizes (Inlet & Outlet):3/4'' & 1'', 1'' & 1-1/4'', 1-1/2'' & 2'', 2'' & 2-1/2''


  • Hot water boiler, heat exchangers and generators.