Our hydroformed metal bellows constructions are often requested for utilization as metal expansion joints.

They are used in plenty of different industrial applications such as machinery, automotive or air conditioning systems


Where systems or piping designs are subject to thermal expansion, vibration, or pressure, metal expansion joints are needed to preserve the integrity. The installation of a metal bellows expansion joint dampens mechanical vibrations or cyclical movements in multiple directions, caused for example, by motors, turbines, pumps, and compressors. Other reasons to be named include inertial forces, misalignment or foundation settlement.

Since 1956 Mera Bellows has been a pioneer and continues today to be a leader in the design and large-scale manufacturing of hydroformed metal bellows and expansion joints. The company is specialized in the high-precision processing of small and thin-walled metallic compensators. In order to design – and decide for a metal expansion joint, many parameters must be considered. Is the surface of particular interest – e.g. when using corrugated tubes as flexible connector in vacuum components? Besides that, has the expansion joint a sealing function or are media flowing through? The working stroke and pressure characteristics are especially important to decide for the necessary amount of walls. For vacuum applications, single-ply expansion joints might be sufficient, especially to ensure low spring rates. Many other (e.g. sealing) applications need, at minimum, two-ply bellows in order to withstand pressure peaks and guarantee safe use. Different liquids and gases, permanent vibration or extreme temperatures (for instance in aerospace) require special materials. After discussing the dimensional parameters, also the type and length of the bellows neck need to be specified – e.g. weld ends or weather a bellows- assembly with flanges is needed.


Compensation types of metal expansion joints


Compensators for industrial applications are differentiated on the basis of three basic types of movement: axial, lateral and angular.

If changes in dimensional length of the material are the concern, axial expansion joints are used, e.g. to compensate thermal expansion, a common problem in piping systems due to the physical properties of metal. These expansion joints take up relatively little space if required and can be made from a wide variety of materials. Mostly they are requested in stainless steel, such as for solar thermal systems. Stainless steel expansion joints have a great tensile strength and are produced to withstand high pressure. Mera Bellows offers compensators of different stainless steels such as 1.4301, 1.4404, 1.4571 or 1.4541.

Lateral expansion joints are commonly installed in right angle redirections of piping systems. They compensate the relative displacement of one end of the bellows to the other one by rotating in angular direction, but are – in contrast to angular expansion joints – independent expansion systems.

Angular expansion joints provide almost unlimited elongation absorption, but also require a change in pipe direction. Because two or three of these metal expansion joints are necessary to form a system, angular expansion joints require more space in comparison to axial expansion joints. An advantage that comes with this is the reduced load on anchor points.

High-end metal expansion joints based on Mera Bellows metal bellows are the perfect choice in order to find individual solutions. Due to their customized manufacturing, the precision bellows expansion joints can demonstrate their strength in a wide variety of applications.


Advantages of metal expansion joints manufactured by Mera Bellows


  • High quality standards within our German group
  • Manufacturing facilities in Poland enable us to offer competitive prices
  • On-time delivery
  • Customized solutions
  • Superior and personalized customer service
  • Seamless and welded constructions
  • Manufacturer with cutting-edge industry expertise
  • 100% leak testing for all bellows and metal expansion joints
  • Wide variety of materials