Expansion Joints - Type MUX | Macoga

Macoga MUX Expansion Joints

Macoga MUX are metallic expansion joints of the thick wall type, featuring a high convolution profile and fabricated from single-ply heavy gauge metal sheet. These units are specified where piping or equipment conditions require a robust bellows geometry, as opposed to conventional thin-wall designs.

Technical Specifications

• Series: Thick wall, MUX type
• Size Range: DN250 to DN8000
• Convolution Height: up to 90 mm for MUX
• Construction: single or multiple convolutions
• End Connections: flanged, weld ends, or bellows-only element
• Geometry: circular, oval, or custom shapes on request

Movements and Loads

MUX type can be engineered for axial, lateral, and angular movement, in single or multiple planes, depending on component geometry and project calculations. No internal pressure thrust restraint is provided; main anchors and pipe guides must be designed accordingly.

Materials

Material selection is based on temperature, pressure, operating cycles, and process media:

• Stainless steels: 304, 321, 316, 316L, 310, 309
• Nickel alloys: Inconel, Incoloy, Hastelloy
• Carbon/alloy steels: P265GH, 16Mo3, 13CrMo44

Typical Applications

Used in heat exchangers, furnaces, furnace ducting, blast furnace pipework, flue gas lines, hot process gases, and large-diameter special piping. Selection must consider not only DN but also pressure, temperature, movement, fatigue cycles, material, and anchoring method.

Installation and Inspection

Not intended for misalignment correction. Bellows must be protected from impact, scoring, arc strikes, and weld spatter. Transport bars (yellow) must be removed before pressure testing; use chloride-free water for hydrostatic tests.