Expansion Joints - Type MWA | Macoga

Macoga MWA Axial Expansion Joints

The Macoga MWA series are metallic axial expansion joints of the single unrestrained type, featuring a single convoluted bellows and weld ends. They are primarily used to absorb axial thermal expansion in straight pipe runs. The allowable movement is determined by project-specific design parameters.

Design Considerations

The MWA type does not restrain pressure thrust. Properly engineered main anchors, directional anchors, and pipe guides are required, calculated for system pressure, effective area, thermal movement, and pipeline loads.

Typical installation configurations:

• Between two main anchors in a straight pipe section
• Downstream of a change in pipe direction
• In long straight runs with an intermediate fixed point
• At nodes where two pipeline sections meet

MWA vs MFA / MFG

• MWA: Weld ends, suitable for permanent connections in the piping system.
• MFA: Fixed flanges.
• MFG: Loose flanges.

Selection depends on assembly method, accessibility, disassembly requirements, and project piping class.

Applications and Media

Used in industrial networks for steam, hot water, compressed air, exhaust gases, process fluids, and auxiliary circuits, provided that material compatibility, pressure, temperature, and chemical resistance are confirmed on the nameplate and project data sheet.

Installation and Inspection

MWA joints must not be used to compensate for misalignment. The bellows should be protected from mechanical impact, welding arcs, and splatter. Remove yellow transport bars before hydrostatic testing. For water tests, use chloride-free water.

FAQ

Is an actuator required?
No. This is a passive piping component.

What is checked during maintenance?
Leakage, external corrosion, loose mechanical parts, condition of guides/anchors, unexpected vibration, and accumulation of debris between convolutions.