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Fisher™ EZH and EZHSO Series
EZH (Spring-to-Close) and EZHSO (Spring-to-Open) Series regulators are accurate pilot-operated, pressure balanced, soft-seated regulators.
They are designed for use in high pressure natural gas transmission/city gate stations, large capacity distribution systems, and power plant feeds. They provide smooth, reliable operation, tight shutoff and long life.

EZH CAD Drawings and Models: Click here
EZHOSX CAD Drawings and Models: Click here

Fisher™ EZH and EZHSO Series


Available Configurations
Type EZH (Spring-to-Close) and EZHSO (Spring-to-Open): Control range of 14.5 to 1160 psig / 1 to 80 bar
Type EZHOSX and EZHSO-OSX: Type EZH and EZHSO with integrated Type OS2 slam-shut device
Body Sizes and End Connection Styles
Body Sizes: NPS 1, 2, 3, 4, 6, 8, 12x6 / DN 25, 50, 80, 100, 150, 200, 300x150
End Connections: NPT, CL150 RF, CL300 RF, CL600 RF, BWE, SWE
Maximum Allowable Pressures
Inlet Pressure: 1500 psig / 103 bar
Outlet (Casing) Pressure: 1500 psig / 103 bar
Emergency Casing Pressure: 1500 psig / 103 bar
Outlet Pressure Range
14.5 to 1160 psig / 1.0 to 80.0 bar
Temperature Capabilities
Nitrile (NBR) Version: -20 to 180°F / -29 to 82°C
Fluorocarbon (FKM) Version: 0 to 180°F / -18 to 82°C
Polyurethane (PU): All body sizes except NPS 3 to 4 / DN 80 to 100: -22 to 180°F / -30 to 82°C, NPS 3 to 4 / DN 80 to 100 Sizes: -4 to 180°F / -20 to 82°C
Hydrogen Configurations
The EZH was validated for hydrogen service through extensive high-pressurehydrogen testing to analyze shutoff performance and material compatibility. For additional details regarding the evaluation and testing, please refer to “Blending Hydrogen with Natural Gas : Technical Factors to Consider”.


  • Absolutely No Atmospheric Bleed—Eliminates nuisance and wasteful bleed gas to atmosphere by utilizing a pilot-operated control system, which bleeds 100% of the gas to the downstream system.
  • Bubble-Tight Shutoff—A knife-edged metal plug and soft seat provide bubble tight shutoff for use in applications where positive shutoff is required such as dead-end systems.
  • Long Life in Severe Service Applications—The metal plug design deflects particles and debris away from the soft-seat, which gives excellent particle erosion resistance, prolonging service life.
  • Failure Mode Options—The Type EZHSO spring-to-open design can be utilized to maximize uptime while the Type EZH spring-to-close design can be utilized to protect downstream assets. For many customers, combining the two technologies with a Type EZHSO worker and Type EZH monitor incorporates the best of both worlds.
  • Precise Pressure Control—Provides stable and accurate downstream pressure control regardless of load changes or inlet pressure variations.
  • Quiet Operation—The Whisper Trim™ Cage option reduces noise by up to 8 dBa at the source, eliminating the need for expensive path treatments such as insulation, buried valves, and enclosures which only mask noise.
  • Full Pressure Rating—The equal inlet and outlet pressure rating of 1500 psig / 103 bar, which allows easier selection and requires no special startup or shutdown procedures.
  • Hydrogen Ready - Products have been evaluated for material compatibility, potential leakage and permeation, and susceptibility to embrittlement for Hydrogen applications. Based on an extensive evaluation and testing program, EZH Series configurations are available for use in Hydrogen applications.