Axial expansion joints KMA

Axial expansion joints (KMA) are one of the simplest designs of metal expansion joints after universal KM. Due to the special geometry of the corrugation, these expansion joints perfectly perceive and compensate for movement along their axis. The design of the axial expansion joint can include an external casing, an internal screen, additional cross-stability limiters, as well as pre-tensioning devices.

Axial expansion joints (KMA) can be equipped with various end fittings. Standard are welded and flanged connections, less often used threaded. On request, this type of expansion joint can be completed with end parts according to the customer's drawing. KMA expansion joints are made of various steel grades: St. 3, St. 20, St. 09G2C, St. 12X18H10T, St. 10X17H13M2T, Incoloy 800, Incoloy 825, and others on request;

Technical characteristics of KMA expansion joints:

Diameter: from 15 mm to 4000 mm
Working pressure: from vacuum to 10 ATM*
Working environment temperature: -240 to 1200°C
The construction length is selected individually, taking into account the needs and wishes of the customer.

Given its design and compensating capabilities, this type of expansion joints is most often used on straight sections of pipe systems, where it is important to compensate only for the axial movement of the pipeline. An example is water and heat supply systems for public utilities.

This type of expansion joints are not unloaded from internal pressure, it is necessary to take into account the load when designing. They require the correct choice of locations in the pipeline system. They can be used for most compensation schemes.

* expansion joints for higher working pressure can also be developed on request.