Description 
The Generant Series APRV, Absolute Pressure Relief Valve, 
is a spring reference over pressure protection device for 
applications requiring constant set pressure independent of 
changes in ambient pressure (altitude).  The valve was 
developed primarily for use with liquid helium dewars and the 
valve has been extensively tested to verify that the valve can 
withstand the extreme cold environment (FS Seals).  Valves 
are constructed primarily of brass, with the seal and stainless 
steel spring being the only non-brass components.  Valves 
come factory preset with set pressures ranging from 15.0 to 
24.0 PSIA (1.02 to 1.65 Bar).  Relief pressure can be 
discharged to atmosphere or to a downstream connection.   
 
Features 
 
• Supplied Factory Preset 
• 100% Factory Tested for Leakage, Crack and 
Reseat Performance  
• Minimal Set Pressure Drift due to change in ambient 
pressure 
• Qualified for Extreme Low Temperature applications 
• High Flow Capacity and Excellent Reseat 
Performance 
• Discharge to Atmosphere or Inline Piping 
Configurations 
 
Technical Data 
 
Set Pressure Range:  15.0 to 24.0 PSIA (1.02 to 1.65 Bar) 
Factory Set Tolerance:  ± 0.5 PSI 
Reseat: 92% of Set Pressure in PSIA 
Temperature Rating:  -80º F to 350º F (-62º C to 176º C) 
   
         
Materials of Construction 
  
Component Material 
Body, End Cap* Nickel Plated CDA 360 Brass, 
ASTM B16 
Poppet, Adjustment 
Screw, Nuts, Ferrules CDA 360 Brass, ASTM B16 
Bellows Brass and 300 Series Stainless 
Steel 
Seals Fluorosilicone 
 
 NOTE: Seals lubricated with Krytox ®  
 *applicable only for inline versions (APRV)