Kunkle Series 900 Safety relief valves

Safety And Relief Products

Bronze, steel and stainless steel safety relief valves for air, gas, steam, liquid and vacuum service that meet ASME Section VIII, ‘UV’; Section I, ‘V’, are National Board certified and PED certified for non-hazardous gas


  • Heavy duty cast valve bodies.
  • Seats lapped to optical flatness.
  • Available with resilient soft seats for superior leak-free performance.
  • Standard SS spring for temperatures to 550°F (288°C). Optional alloy spring to 800°F (427°C).
  • Threaded cap standard (back pressure tight). Maximum back pressure 50 psig [3.4 barg].1
  • Hex on valve nozzle provides for easy installation.
  • Warn ring offers easy adjustability.
  • Pivoting disc design offers exceptional seat alignment.
  • Guide to nozzle ratio reduces friction.
  • Full nozzle design for optimum flow performance.
  • Threaded side outlet for piped off discharge to eliminate fugitive emissions.
  • Each valve tested and inspected for pressure setting and leakage.

General Application

Suitable for air/gas compressors, liquid filled pressure vessels/systems, high temperature/ pressure hot water boilers, for pressure vessels containing air, gas or steam and process and industrial applications requiring steel/stainless steel construction. Also for vacuum service.

Technical Data

Connections: Threaded NPT, BSPT, flanged or Tri-clover
Temperature range: -320° to 800°F (-195° to 427°C)
Pressure range: 3 to 1400 psig (0.2 to 96.5 barg)
Vacuum range: 6″ to 29″ HG (200 to 1000 mbarg)
Code: ASME I, VIII and PED

Back pressure increases set pressure on a one to one basis and reduces capacity. Back pressure in excess of 10% of set pressure is not recommended.