Expansion Joints - Type MWC | Macoga

Macoga MWC Gimbal Expansion Joints

The Macoga MWC is a metallic expansion joint of the gimbal type, supplied with welded ends. It incorporates two pairs of hinges mounted on a common floating gimbal ring, allowing the bellows to accommodate angular movement in any plane. The corresponding flanged version is designated MFC.

Operation and Limitations

The gimbal ring, hinges, and pins are engineered to absorb pressure thrust and shear loads. As a result, main anchors for pressure thrust are not required, unlike unrestrained axial expansion joints.

Permitted movement:

• Angular: In one or multiple planes.
• Axial: Not permitted.
• Lateral: Not applicable for a single unit.
• Bellows torsion: Must be avoided.

Typical Applications

MWC gimbal joints are used in piping systems for steam, hot water, thermal oil, flue gases, and process gases. Commonly installed in pairs or combined with a hinged joint, two gimbal units can absorb angular movement in any plane. In a configuration with two gimbals and one hinged joint, vertical expansion is controlled when movement occurs in a single plane.

MWC vs. MFC Selection

• MWC: Welded ends, suitable for permanent integration into the piping class.
• MFC: Same functional principle, flanged connection for disassembly or easier replacement.

Selection must consider DN, pressure, temperature, angular movement, operating cycles, bellows material, pipe weight, and media compatibility.

Installation and Inspection

MWC joints are not intended for correcting misalignment. Protect bellows from impacts, scratches, arc strikes, and weld spatter. Do not suspend the unit by gimbals, hinges, or shipping bars. Remove yellow shipping bars before pressure testing; use chloride-free water for hydrostatic tests.

FAQ

Does it absorb axial movement?
No. The MWC is a gimbal type for angular movement only.

Is an actuator required?
No. The unit operates passively, responding to piping movement.