Kunkle Safety Relief Valve Models 6252 & 6254 Certified Valves

One of our most popular valves, Kunkle valve 6252 is steam, air and gas certified. Made of cast iron and stainless steel trim, this heavy duty valve is used on steam boilers, steam generators, and pressure reducing steam vessels such as tanks, receivers and oil/gas separators.

Kunkle valve 6254 is the same as 6252 plus it is certified for low-pressure steam heating boilers.

Model Detail Description:

ASME Section I Steam and ASME Section VIII, Air, Steam and Gas “UV” National Board Certified. Model 6254 ASME Section IV “HV,” National Board Certified. PED Certified for Non-Hazardous Gas.

  • Model 6252: Cast iron, enclosed spring, stainless steel (SS) trim.
  • Model 6254: Same as Model 6252 except certified for ASME Code Section IV, Low-pressure Steam Heating Boilers. Set 15 PSIG [1.0 barg] only. J through P orifice only.


  • Heavy-duty construction of high-quality cast iron with stainless steel semi-nozzle trim and disc.
  • Bolted bonnet design for easy maintenance.
  • Seats lapped to optical flatness.
  • Dual control rings offer easy adjustability for precision opening with minimum preopen or simmer and exact blowdown control.
  • Heavy-duty lift lever assembly.
  • Adjustments are factory sealed to prevent tampering or disassembly.
  • Each Kunkle valve is tested and inspected for pressure setting and leakage.


  • Steam boilers and generators.
  • Pressure-reducing stations.
  • Air/gas compressors — reciprocating or rotary.
  • Pressure vessels, including tanks, receivers, intercoolers, oil/gas separators, lines.

Pressure and Temperature Limits:

  • Model 6252:
    • 10 to 250 PSIG [0.7 to 17.2 barg]
    • -20° to 406°F [-28° to 208°C]

Please refer to the Kunkle Catalog or Contact Us for additional information.

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