Expansion Joints - Type MFG | Macoga

Macoga MFG Axial Expansion Joints

Macoga MFG are metallic axial expansion joints of the single unrestrained type, featuring a single bellows and loose flanges. They are primarily used to absorb axial thermal expansion in straight pipe runs, with limited capability for other movements within the design parameters of the unit.

Operation and Anchoring

The MFG type does not absorb pressure thrust. Main anchors, directional anchors, and axial guides are required, calculated for pressure, effective area, thermal movement, and piping loads. Standard installation is between two main anchors in a straight section.

Typical Applications

Suitable for industrial piping systems requiring flanged connections and easier flange alignment:

• Steam, hot water, condensate lines
• Thermal oil and process utility circuits
• Compressed air and inert gases
• Large-diameter HVAC networks
• Piping requiring disassembly without cutting

Selection is based on DN, PN/Class, temperature, axial movement, operating cycles, bellows material, internal sleeve, and media compatibility.

MFG vs MFA / MWA

• MFG: Loose flanges, useful for rotational alignment during assembly.
• MFA: Fixed flanges.
• MWA: Weld ends.
• All three are single unrestrained and require external absorption of pressure thrust.

Installation and Sealing

Not intended for misalignment correction. Verify nameplate data, flow direction (with internal sleeve), gaskets, guides, and bellows cleanliness. Protect bellows from impacts, arcs, and weld spatter. Remove yellow transport bars before pressure testing; use chloride-free water for hydrostatic tests.

FAQ

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

What is checked during maintenance?
Flange leakage, pressure loss, vibration, corrosion, guides/anchors, and debris between bellows convolutions.