Expansion Joints - Type MTI | Macoga

Macoga MTI Axial Expansion Joints

Macoga MTI are metallic axial expansion joints of the single unrestrained type, featuring a single bellows and internal BSP or NPT threads for connection to small-bore piping systems. They belong to the same family as MWA, MFA, MFG, MTE, and MQP, but are distinguished by their threaded internal connection.

Network Operation

MTI type is primarily intended for axial compensation of thermal expansion. It does not absorb pressure thrust; therefore, the piping system must be equipped with properly calculated main anchors, directional anchors, and pipe guides.

Application Selection

Suitable for auxiliary and process piping where threaded connections are required instead of flanges or welding:

• HVAC and hot/cold water circuits
• low-diameter steam lines, subject to data sheet limitations
• compressed air
• auxiliary industrial circuits
• non-corrosive liquids or gases, depending on construction materials

Pressure, temperature, and media compatibility must be verified against the unit nameplate and order specifications. Installation instructions require confirmation that nameplate data matches actual operating conditions.

Variant Differences

• MTI: internal BSP or NPT thread.
• MTE: external BSP or NPT thread.
• MWA: weld ends.
• MFA: fixed flanges.
• MFG: loose flanges.
• MQP: quick press connection for HVAC.

Installation and Inspection

Not suitable for correcting misalignment. Bellows must be protected from impact, welding arcs, splatter, and foreign objects. Remove yellow transport bars before pressure testing. For hydrostatic tests, use chloride-free water.

Standards and Certifications

Manufacturer certifications include PED 2014/68/EU Module H, ISO 9001:2015, DIN ISO 3834-2, ASME Certification Mark, TÜV AD 2000-Merkblatt HP0, Lloyd’s Register, and DNV-GL Type Approval.