Kunkle Pressure Relief Valve Models 330, 330S, 333S Certified Valves, Model 230 (Non-Code)

Made with aluminum, these valves are certified for non-hazardous gas. Used with multi-stage high-pressure compressors, intercoolers and aftercoolers, High pressure receivers and storage bottles as well as thermal expansion relief, these lightweight valves aluminum parts are anodized for corrosion resistance making this valve resistant to both environmental and internal corrosion.

Model Descriptions:

ASME Section VIII, Gas, “UV” National Board Certified. PED Certified for non-hazardous gas.

  • Model 230: ¼” male NPT – 300/1500 PSIG.
  • Model 330: ¼” male NPT – 1000/5500 PSIG. Aluminum housing, stainless steel (SS) trim (seat and disc with synthetic insert). Sidewall discharge.
  • Model 330S: Same as Model 330 except SS body suitable for 1000/6500 PSIG.
  • Model 333S: Same as Model 330S except ¼” female NPT side outlet. Pressure-tight cap.


  • Lightweight aluminum construction. Resistant to environmental and internal corrosion.
  • Model 230 (non-code) has direct spring-loaded design with synthetic disc insert.
  • Model 330 series incorporates a differential mechanism that maintains a predetermined seat-contact load.
  • The full spring load is never imparted to synthetic disc insert (Models 330, 330S and 333S only).
  • Seat tightness increases to maximum as inlet pressure approaches the opening pressure.
  • Each Kunkle valve is tested and inspected for pressure setting and leakage.


  • Multi-stage high-pressure compressors, intercoolers and aftercoolers.
  • High-pressure receivers and storage bottles.
  • Thermal expansion relief.

Pressure and Temperature Limits:

  • Model 230
    • 300 to 1500 PSIG [20.6 to 103.4 barg]
    • -20° to 185°F [-28.9° to 85°C]
  • Model 330
    • 1000 to 5500 PSIG [68.9 to 379.2 barg]
    • -20°to 185°F [28.9° to 85°C]
  • Model 330S
    • 1000 to 6500 PSIG [68.9 to 448.1 barg]
    • -20°to 185°F [28.9° to 85°C]
  • Model 333S
    • 1000 to 6500 PSIG [68.9 to 448.1 barg]
    • -20°to 185°F [28.9° to 85°C]

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

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