Rubber expansion joints - Rubber expansion joint - 2831A | Genebre

Genebre 2831A – ANSI 150 Rubber Expansion Joint

The Genebre 2831A is a single-arch, flanged rubber expansion joint designed for piping systems requiring vibration absorption, noise reduction, and compensation for axial or lateral movement. The body is constructed from EPDM reinforced with nylon; flanges and retaining rings are galvanized carbon steel.

Technical Specifications

• Connection: ANSI 150 B16.5 flanges
• Sizes: 1 1/4” to 20” / DN32 to DN500
• Max. working pressure: 16 bar up to 12”, 10 bar for 14”–20”
• Operating temperature: -10 °C to +105 °C
• Burst pressure: 30 bar
• Max. vacuum: 400 mbar

Piping Movement Compensation

Depending on size, allows axial compression 10–28 mm, axial elongation 6–16 mm, lateral movement 9–25 mm, and angular deflection 10° or 15°. Movement limits must be coordinated with pipe anchors, guides, and actual thermal expansion calculations.

Applications and Media Compatibility

Used in pump stations, HVAC, chilled/hot water circuits, and auxiliary industrial piping. EPDM is suitable for water and aqueous media. Not recommended for mineral oils, fuels, or hydrocarbons without chemical compatibility verification.

Installation

No additional sealing gasket required; the elastomer body provides the sealing surface. Tighten bolts in a cross-pattern, gradually and evenly. For pump connections, maintain 1 to 1.5 × DN distance from pump nozzle.

Difference from 2831

2831A is specified for ANSI 150 flange systems. Type 2831 is for DIN/EN flanged connections. Selection must consider both DN and flange standard.

Maintenance

No lubrication required. Periodic inspection should check for bolt loosening, corrosion, leakage, and elastomer deformation. Recommended tightening torques: 50 Nm (1 1/4”–4”), 60 Nm (5”–6”), 80 Nm (8”–14”), 100 Nm (16”–20”).

FAQ

Can it be fitted with an actuator?
No. This is a passive piping component.

When should it be replaced?
Replace fully in case of partial or total failure, after isolating, depressurizing, and draining the line.