Expansion Joints - Type MFL | Macoga

Macoga MFL Lateral Expansion Joints

Macoga MFL expansion joints are metallic, universal lateral tied type, with flanged ends. Construction includes two bellows, an intermediate pipe, and a tie rod system designed to absorb thrust forces from internal pressure. The welded-end equivalent is the MWL series.

Movement Capabilities and Limitations

MFL type is primarily used for lateral displacement of piping in one or more planes. Lateral capacity depends on the angular deflection of each bellow and the length of the intermediate pipe. With two tie rods at 180°, the joint accommodates lateral and angular movement. With three or more tie rods, movement is limited to lateral offset only.

Typical Applications

• Z-shaped piping sections
• steam, hot water, and thermal oil networks
• process gases and auxiliary industrial circuits
• installations requiring flanged disassembly
• lines with lateral offset in one or multiple planes

Selection must consider DN, PN/class of flange, temperature, pressure, lateral movement, operating cycles, bellow material, gasket type, and media compatibility.

MFL vs MFT / MFY

• MFL: two bellows, universal lateral tied, for lateral movement.
• MFT: single bellow, single tied, mainly for axial movement.
• MFY: double hinged, lateral/angular movement in a single plane only.

Installation and Inspection

Not intended for misalignment correction. Prior to installation, verify nameplate data, flow direction (with internal sleeve), gasket compatibility, guides, and anchors. Protect bellows from impacts, scratches, arc strikes, and weld spatter.

Remove yellow transport bars before pressure testing. Hydraulic tests require chloride-free water. Maintenance includes checks for leakage, pressure loss, vibration, corrosion, loose tie rods, and debris in convolutions.