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FE 25/50 Gas Pressure Regulator
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CSA 
Measurement Canada 
Hydrogen Compatible Description
The FE25 / FE50 is a two-stage gas pressure regulator by Pietro Fiorentini. It is particularly suitable for low pressure natural gas distribution networks for residential and commercial users. It should be used with previously filtered non-corrosive gases including biomethane and natural gas blended with hydrogen.
According to the European Standard EN 334, it is classified as Fail Close because it is always supplied with an overpressure protection device (slam shut valve).
The FE25 / FE50 is Hydrogen Ready for NG-H2 blending.
Features- Accuracy class AC: 10
- Connections: In-line 3/4” or 1” NPT according to ANSI B1.20.1, other configurations or connections on request
- Lock-up pressure class SG: 20, minimum 3” w.c. | 0.75 kPa
- Inlet pressure: 1.45 psig to 125 psig | from 10 kPa to 0.86 MPa
- Ambient temperature: standard version from -20°F to +150°F | -30°C to +65°C, arctic version from -40°F to +150°F | -40°C to +65°C
- Range of downstream pressure:
- Wds from 5.2” w.c. to 2.6 psig | 1.3 kPa to 18 kPa for BP, from 4.35 psig to 5.8 psig | 30 kPa to 40 kPa for MP
- Wdso from 14” w.c. to 3.5 psig | 3.5 kPa to 24.1 kPa for BP, from 4.3 psig to 11.6 psig | 30 kPa to 80 kPa for MP
Specifications
Specifications
Brand
Certifications & Approvals
CSA Measurement Canada Hydrogen Compatibility %
Hydrogen Compatible up to 100% 
Hydrogen Compatible up to 30% 
Hydrogen Compatible up to 20% Capacity
- FE6: 6 Stm³/h
- FE10: 10 Stm³/h
- FE25: 25 Stm³/h
- FES: 50 Stm³/h
Accuracy Class AC
- Up to 5
Lockup Pressure SG
- Up to 10
Inlet Pressure
- 8.6 bar Max.
Downstream Pressure Regulation Range
- TR: 180 to 500 mbar
- BP: 13 to 180 mbar
Enclosure, Body Material
- Body: Zamak, or Aluminum on Request
Material of Construction
- Seat: Zamak
- Cover: Zamak, Aluminum on Request
- O-Ring: Nitrile Rubber
Diaphragm Material
- Nitrile Rubber (TR: Linen Rubber)
Inlet
- G 1/2" ISO 228/1
Outlet
- G 1" Outlet in Line
- G 3/4" Angled Outlet
Ambient Temperature
- -40° to 60° C
Inlet Temperature Range
- -20° to 60° C
- Up to -10° to 60° C Standard
Why Choose the Pietro Fiorentini FE 25/50
Why Choose the Pietro Fiorentini FE 25/50
Value Elements
- Optimized Design for Clearance Compliance
- The FE 25/50 is engineered to reduce or fully eliminate vent and opening clearance requirements, making it ideal for tight spaces or where strict regulations apply.
- Balanced Design and Dual-Stage Cut
- Thanks to its internal balanced mechanism and dual-stage cut configuration, this regulator can maintain stable outlet pressure across a wide range of inlet pressures — all with just one unit. That means no more orifice changes to accommodate varying pressure demands.
- Highly Stable Performance
- Whether the demand is high or low, the FE 25/50 delivers consistent and reliable outlet pressure, ensuring optimal appliance operation.
- Built-in Safety with Slam Shut
- Ideal for Canadian installations, the FE 25/50 is OPCO-ready. For enhanced safety, it features a built-in slam shut device for overpressure protection, adding peace of mind to your installations.
- Low Venting Emissions
- Compliant with both CSA 6.18 (Outdoor) and CSA 6.22 (Indoor) standards, this unit drastically reduces gas venting emissions compared to conventional models.
Comparison vs. Next Best Alternative
- Fewer Regulators, Fewer Headaches
- Its balanced design handles a much wider range of demand than the competition. No need to carry or switch between multiple regulators and orifices for different installations.
- Space-Saving Design
- With a compact footprint, the FE 25/50 fits easily into tight installations where others might struggle.
- Ultra-Low Venting
- This regulator vents 2.5% or less of the gas volume typical of competitor models — a significant advantage in minimizing environmental impact and meeting regulatory requirements.
Where Do I Use This Product and Why?
- Ideal for Residential and Light-Duty Commercial Settings
- Perfect for spaces where venting options are limited or restricted — this regulator’s design excels where others fail due to clearance constraints.
- Versatile Across Demand Ranges
- Whether you're dealing with high or low gas demand, the FE 25/50 offers a steady, reliable output without the need for tuning or switching out components.
