Expansion Joints - Type MTE | Macoga

Macoga MTE Axial Expansion Joints

Macoga MTE are metallic axial expansion joints, single unrestrained type, featuring a single convoluted bellows and external BSP or NPT threads. The threaded connection is suitable for small bore piping where flanged or welded ends are not specified in the piping class.

Operation and Limitations

MTE type is primarily used to absorb axial thermal movement in straight pipe runs. As an unrestrained design, it does not absorb pressure thrust. Main anchors, pipe guides, and supports must be engineered and installed prior to commissioning.

Typical Applications

• HVAC systems (hot and chilled water)
• Small bore auxiliary steam lines
• Compressed air networks
• Auxiliary circuits in industrial plants
• Non-corrosive liquids or gases, subject to material compatibility

Final selection must confirm pressure rating, temperature, axial movement, cycle count, and material compatibility with the process fluid.

Comparison with Other Macoga Types

• MTE: External BSP/NPT thread
• MTI: Internal BSP/NPT thread
• MWA: Weld ends
• MFA: Fixed flanges
• MFG: Loose flanges

Installation and Inspection

MTE joints are not intended for misalignment correction. Protect bellows from mechanical damage, arc strikes, and weld spatter. Remove yellow transport bars before pressure testing. For hydrostatic tests, use chloride-free water.

Standards and Certifications

Macoga single unrestrained series are available with markings and approvals such as EJMA, CE, ISO 9001, TÜV / AD 2000-Merkblatt HP0, and DIN ISO 3834-2, depending on project documentation requirements.

FAQ

Is an actuator required?
No. Operation is passive and depends on thermal movement of the piping.

What is checked during maintenance?
Leakage, pressure loss, external corrosion, vibration, condition of guides/anchors, and debris between convolutions.