Full Face Rubber Flanged Expansion Joints - MAC-FC / Gimbal | Macoga

MACOGA MAC-FC Gimbal – Full-Face Elastomeric Angular Movement Expansion Joint

The MAC-FC is an elastomeric gimbal-type expansion joint designed for piping systems requiring angular movement in multiple planes, with simultaneous mechanical restraint of pressure thrust. The gimbal ring, hinges, and pins absorb axial forces from internal pressure and shear loads, eliminating the need for main anchors when properly engineered.

Operating Principle

Movement is achieved via two pairs of hinges connected to a common floating gimbal ring. This configuration allows single-plane and multi-plane angular movement but is not intended for axial or lateral displacement. The mechanical assembly also restricts torsion of the elastomeric body.

Construction

• Full-face elastomeric flange with metallic backing flanges
• Available with single or multiple arches
• Gimbal ring: round (controls torsional moment) or square (controls buckling instability)
• No main anchors required for pressure thrust if system is correctly designed

Materials and Media Compatibility

Elastomer selection is based on media, temperature, and chemical compatibility:

• EPDM: water, hot water, seawater, oil-free air, non-hydrocarbon chemicals
• EPDM HT: applications up to 140 °C
• NBR: oils, fuels, gases, hydrocarbons; not suitable for steam or hot water
• SBR / Natural Rubber: slurries, sewage, liquids with solids
• FKM / Viton: hydrocarbons, oils, solvents, chemicals up to 150 °C

Standards and Selection

Design is based on FSA Non-Metallic Expansion Joints Technical Handbook, ASTM F1123-87, and PED 2014/68/EU. Full-face series can be drilled to EN, ANSI, AWWA, JIS, or project-specific patterns.

Comparison: MAC-FC Gimbal vs. MAC-FP Hinged

The MAC-FP hinged joint permits angular movement in a single plane only. The MAC-FC gimbal is selected when angular movement may occur in multiple planes and mechanical pressure thrust restraint is required.

No actuator is included. Selection is based on DN, pressure, temperature, media, angular movement, vacuum requirement, gimbal type, and allowable piping loads.