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Fisher™ CS400 Pressure Reducing Regulators
Fisher CS400 Series direct-operated, spring-loaded regulators provide pressure-reducing applications for commercial and light industrial installations.
This flexibility is provided by the numerous body sizes and end connections, outlet pressure settings, orifice sizes, as well as the option for internal or external pressure registration. In addition to application flexibility, the CS400 Series offers multiple overpressure protection options to meet your demands on application requirements.

CAD Drawings and Models: Click Here
Fisher™ CS400 Pressure Reducing Regulators


Available Configurations
Stand-Alone Regulator, Non-relief, Token relief, Internal or External pressure registration, Integral True-Monitor, VSX4 Slam-Shut Module
Hydrogen (H2)
Up to 25% Hydrogen blend (by Volume)
100% Hydrogen ready
Body Sizes and End Connection Styles
Gray CI: 1-1/4, 1-1/4x1-1/2, 1-1/2, 2 NPT, NPS2/DN50, CL125 FF
DI: 1-1/4, 1-1/2, 2NPT, Rp 1-1/4, 1-1/2, 2, NPS2/DN50, CL125 FF, CL150 FF, or PN10/16
ST: 1-1/4, 1-1/2 NPT, Rp 1-1/4, 1-1/2
Maximum Operating Inlet Pressure
125 psig / 8,6 bar
Outlet Pressure Range
3.5-inches w.c. to 5.5 psig / 9 to 380 mbar in nine ranges
Maximum Emergency Outlet Pressure (Casing)
25 psig / 1,7 bar
Maximum Outlet Pressure to Avoid Internal Parts Damage
5 psi / 0,34 bar over set point
Maximum Operating Outlet Pressure
5.5 psig / 380 mbar
Pressure Registration
Internal or External
Token Relief
Cg = 67
Temperature Capabilities
-20° to 150°F / -29° to 66°C
Approximate Weights
Threaded Body:
Type CS400: 9 Pounds / 4 kg
Type CS403: 18.5 Pounds / 8 kg
Type CS404: 11.2 Pounds / 5 kg
Flanged Body: Add 8.6 Pounds / 4 kg to weights listed
Type TM600 True-Monitor™ Specifications
Control Press: 11wc-7.5psi/27-517mbar
Max Op Outlet Press TM600 on CS403:7.5psi/517mbar
Vent:1/4 NPT
Ext Sense: 1/4 NPT
Case Material: AL
Press Reg: Same as Regulator
Type VSX4 Slam-Shut Module Specifications
Vent:1/4 NPT
Ext Sense:1/4 NPT
Case Material:AL
Press Reg:Int or Ext


  • Wide Variety of Body Sizes and End Connections
  • Fixed Factor / Pressure Factor Measurement (PFM) Accuracy Capabilities
  • Field Convertible from Internal Sensing to External Sensing for Wide-Open Monitor Construction
  • Available in Gray Cast Iron, Ductile Iron, and Steel Body Materials
  • Only Standard Tools Required for Pressure Adjustment and Orifice Removal
  • Easy to Maintain
  • Up to 25% Hydrogen blend (by Volume) ready
  • 100% Hydrogen Available - (contact factory)