Model 441-57S & Model 461-57S Natural Gas Pressure Regulators

The Model 441-57S and Model 461-57S natural gas pressure regulators are spring-operated, medium-pressure regulators engineered to deliver near-pilot-operated performance without the complexity of a pilot system. Both models incorporate a proprietary roll-out diaphragm design that dramatically reduces pressure droop as flow increases, resulting in stable, accurate outlet pressure and exceptionally fast response.

Designed for intermediate to large-capacity gas applications, the 57S-series is widely used in gas distribution systems, district regulator sets, city gate and town border stations, monitoring applications, and demanding industrial environments. With a long track record of dependable service spanning decades, these regulators are trusted workhorses in critical gas control systems.

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Product Documents

Model 441-57S & Model 461-57S Features

  • Roll-Out Diaphragm Technology: Unique diaphragm action reduces outlet pressure droop as flow increases, delivering performance similar to pilot-operated regulators.

  • Fast, Stable Pressure Response: Maintains consistent outlet pressure under rapidly changing load conditions.

  • Simple, Spring-Operated Design: Eliminates pilot systems, reducing maintenance requirements and potential freeze-up issues.

  • Standardized, Interchangeable Components: Standard face-to-face dimensions and interchangeable inner valve assemblies simplify servicing and spare parts management.

  • Balanced Valve Construction: Available with single-seat or double-seat balanced valves for precise control across a wide operating range.

  • Multiple Soft-Seat Materials: Molded polyurethane, Buna-N, Viton, and nylon valve seats available to match pressure, temperature, and gas compatibility requirements.

Benefits

  • Near-Pilot Performance Without a Pilot: Achieves excellent regulation accuracy and minimal droop using a purely mechanical design.

  • Exceptional Reliability: Proven design with decades of successful field performance in utility and industrial applications.

  • Rapid Emergency Response: Fast reaction time makes these regulators ideal for monitoring applications and system protection.

  • Simplified Maintenance: Interchangeable components and side inspection plates reduce service time and downtime.

  • Versatile Application Coverage: Suitable for distribution, monitoring, and industrial gas systems across a wide pressure range.

Capability

The 57S-series regulators are designed for demanding medium-pressure gas regulation applications.

  • Application Types: Gas distribution systems, district regulator sets, city gate stations, town border stations, monitoring, industrial processes

  • Gas Compatibility: Natural gas, propane vapor (LPG), air, nitrogen, dry COâ‚‚, and other non-corrosive gases

  • Installation: Indoor or outdoor (not recommended for buried service)

  • Monitoring Capability: Excellent performance as monitor regulators in series installations, capable of quickly assuming control during upstream regulator failure

Specifications

Available Models

  • Model 441-57S: Medium-pressure regulator for larger pipe sizes and higher capacities

  • Model 461-57S: Medium-pressure regulator for intermediate capacity applications

Both models are available with threaded or flanged bodies, multiple valve configurations, and a wide range of spring options.

Pressure Ratings

  • Outlet Pressure Range: 3 to 100 psi (spring dependent)

  • Maximum Inlet Pressure:

    •  Varies by body type and material

    •  Up to 1,000+ psi on select flanged steel configurations

  • Operating Temperature Range: -20°F to +150°F
     

For detailed inlet pressure limits, spring ranges, capacity tables, and dimensional data, refer to the product documents above.

Construction

  • Body Materials: Cast iron, ductile iron, or cast steel (configuration dependent)

  • Diaphragm Housing & Spring Cage: Cast iron or ductile iron

  • Diaphragm: Buna-N with fabric reinforcement (roll-out design)

  • Valve & Trim Materials:

    •  Brass or stainless steel stems and orifices

    •  Soft-seat options in Buna-N, polyurethane, Viton, or nylon

  • Guidance & Sealing: Bushing-guided inner valve with O-ring stem seals for accurate alignment and tight shutoff

Pipe Sizes

  • Model 441-57S: 2", 3", 4", and 6"

  • Model 461-57S: 2"