BelGAS P289 Relief Valve / Back Pressure Regulator

BelGAS P289 Relief Valve / Back Pressure Regulator

Product Description

The BelGAS P289 is a high-performance Relief Valve and Back Pressure Regulator designed to provide reliable overpressure protection and stable upstream pressure control. Operating as a throttling-type relief device, the P289 offers high flow capacity, tight shutoff performance, and exceptional regulation accuracy. Its compact and simplified construction ensures long-term reliability and reduced maintenance requirements.

The large diaphragm area combined with a pitot tube booster enhances the regulator’s responsiveness, enabling smooth and rapid pressure relief—especially beneficial in low-pressure applications. The P289 series is suitable for a wide range of industrial settings and may be applied as an alternative to standard relief valves to protect downstream systems from over-pressurization.

Typical applications include fuel gas relief and gas gathering systems where consistency, durability, and precise pressure control are essential.

Technical Specifications

Operating Performance

• Function: Relief Valve / Back Pressure Regulator

• Design Type: Throttling, high-flow, adjustable set point

• Maximum Inlet Pressure:

  • P289 (1” & 3/4” x 1”): 100 psig (6.9 bar)

  • P289 2” & L289: 25 psig (1.7 bar)

• Available Relief Set Pressure Ranges:
  P289 1” & 3/4” x 1”

  • 1–4.5 psig (0.07–0.3 bar)

  • 4–15 psig (0.28–1.0 bar)

  • 10–20 psig (0.7–1.4 bar)

  • 15–50 psig (1–3.5 bar)

  • 45–75 psig (3.1–5.2 bar)

P289 2” & L289

• 7–18 in. W.C. (0.017–0.045 bar)

• 0.5–2.25 psig (0.035–0.16 bar)

• 1.75–7 psig (0.12–0.5 bar)

• 4–10 psig (0.28–0.7 bar)

Temperature Ratings

• Nitrile / Neoprene Elastomers: –20°F to +150°F

• Fluoroelastomer: 0°F to +300°F

Materials of Construction

P289 (1” & 3/4” x 1”)

• Body & Bonnet: Aluminum

• Diaphragm: Nitrile or Fluoroelastomer

• Gaskets: Neoprene

• O-Rings: Nitrile or Fluoroelastomer

• Pitot Tube: Aluminum

• Spring & Internal Hardware: Zinc-plated steel

• Seat Components: Aluminum (piston design)

P289 2” & L289

• Body:

  • L289: Aluminum

  • P289 2”: Cast Iron

• Bonnet: Aluminum

• Main Seat: Brass or Stainless Steel

• Diaphragm: Nitrile or Fluoroelastomer

• O-Rings: Nitrile or Fluoroelastomer

• Pitot Tube: Brass or Stainless Steel

• Closing Cap: Acetal

• Gaskets: Neoprene / Composite

Dimensions & Weight

• P289 1”: Approx. 2 lbs (0.907 kg)

• P289 2” / L289: Approx. 15 lbs (6.803 kg)

(Exact dimensional drawings available in the datasheet.)

Key Features

• High-flow relief capability

• Adjustable back pressure control

• Tight shutoff performance

• Compact, rugged construction

• Simple maintenance—serviceable in-line

• Rapid response due to large diaphragm area and pitot tube booster

Typical Applications

• Fuel gas relief systems

• Gas gathering pressure protection

• General upstream pressure control