The Sought-After Kunkle Iron Relief Valves for both Steam and Air Service

Not only is Kunkle’s 6252/6254 among their largest valves, also it’s a very sought-after one. You guessed it; we keep several in stock.

For general application, it is suitable for use on steam boilers and generators, pressure reducing stations, reciprocating or rotary air/gas compressors and for pressure vessels including tanks, receivers, intercoolers, oil/gas separators and lines.


  • Valves available National Board certified to ASME sections I, VIII and IV, and PED certified for non-hazardous gas
  • Heavy-duty, high-quality cast iron construction 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 pre-open or simmer and exact blowdown control
  • Heavy-duty lift lever assembly
  • All adjustments factory sealed to prevent tampering or disassembly
  • Each valve tested and inspected for pressure setting and leakage


  • Sizes: 1-1/2 thru 6-inch
  • Pressure Limits: 250 PSIG – 406°F