FITOK relief valves OPEN when system pressure reaches the set pressure and CLOSE when system pressure falls below the set pressure.


  • FITOK proportional relief valves should never be used as safety relief devices as defined in the ASME Boiler and Pressure Vessel Code.
  • FITOK proportional relief valves are not “Safety Accessories” as defined in the Pressure Equipment Directive 97/23/EC.
Proportional Relief Valves Interchangeability(functionality)
Series RV RL-7 RL-8 RM
Corresponding brand and series Swagelok R3A Series Swagelok RL3 Series Swagelok RL4 Series Swagelok R4 Series


  • Set pressure:
    RV series: 7 color-coded springs available for a wide range of set pressure, 50 to 6000 psig @ 70°F (3.4 to 414 bar @ 20°C).
  • Maximum outlet pressure:
    RV series: 1500 psig (103 bar).
  • Orifice size:
    RV series: 0.14″ (3.6 mm)
  • Back pressure:
    Back pressure is the pressure of the outlet of valves. It increases the set pressure of proportional relief valves. RV and RM series: Balanced stem design to eliminate the effect of system back pressure.
  • Working temperature: -10°F to 300°F (-23°C to 148°C).
  • Variety of end connections.
  • Liquid or gas service.
  • Adjustable bonnet cap and adjustable set pressure.
  • Lead seal through lock wire holes to lock proportional relief valve so as to secure a set pressure effectively.
  • Variety of seal materials.
  • Label identifies the set pressure range.