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Fisher™ 634 Series High-Pressure Shutoff Valves
Fisher Types 634 and 634M high-pressure shut-off valves serve to provide overpressure protection by containment.
Type 634 shut-off valve with internal registration is installed between a pressure reducing regulator and a downstream system or equipment. Type 634M shut-off valve with external registration requires a control line and is installed upstream of a pressure reducing regulator.
Fisher™ 634 Series High-Pressure Shutoff Valves


Body Sizes and End Connection Styles
3/4 or 1 NPT
Maximum Inlet Pressure
1500 psig / 103 bar
Maximum Outlet (Casing) Pressure
Type 634: 150 psig / 10,3 bar
Type 634M: 1500 psig / 103 bar
Pressure Registration
Type 634: Internal
Type 634M: External
Temperature Capabilities
-40° to 180°F / -40° to 82°C
Approximate Weight
10 pounds / 4 kg


  • Overpressure Protection without Discharge of Gas
  • Positive Shutoff
  • Application Versatility
  • Easy Maintenance