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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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.

Pipe Sizes

• Model 441-57S: 2", 3", 4", and 6"
• Model 461-57S: 2"

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

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.

Benefits

• Near-Pilot Performance Without a Pilot: Achieves excellent regulation accuracy and minimal droop using a purely mechanical design.
• Freedom From Freeze-Up: Unlike pilot-operated models, this regulator features a larger main valve that prevents ice from clogging the orifice.
• Low Lock-Up Pressures: achieves lower lock-up pressures because its massive roll-out diaphragm maximizes surface area at closure, generating the immense mechanical force needed to tightly shut the valve with minimal pressure buildup.
• 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