bellows expansion joints

Stainless steel bellow expansion joint for Solar thermal energy (Connecting solar panels)

They are used in plenty of different industrial applications but are also supplied thousandfold as corrugated tubes with special endings to connect solar thermal panels.

Piping design or other equipment is often subject to

  • thermal expansion
  • mechanical vibration
  • pressure
  • cyclical movements in multiple directions

that are caused for example by weather, motors, turbines, pumps, or compressors. Other reasons to be named include inertial forces, misalignment or foundation settlement. In such cases, metal expansion joints are needed to preserve the system’s integrity.


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- (to 70mm ID) and thin-walled (less than 0,4mm) metallic compensators.


bellows expansion joints

Formed seamless metal expansion joint to compensate axial movements

In order to design – and decide for a metal expansion joint, many parameters must be considered

  • Which material is suitable? – Stainless steel, Inconel or Hastelloy expansion joints for extreme temperatures (Aerospace)
  • Is the surface of particular interest? – e.g. when using corrugated tubes as flexible connector in vacuum components
  • Does the expansion joint have a sealing function? – Two-ply bellows design to withstand high pressure peaks and guarantee safe use.
  • What is the expected stroke that the metal expansion joint is supposed to perform?

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.


Stainless steel expansion joints for solar thermal systems

Compensators for industrial applications are differentiated on the basis of three basic types of movement: axial, lateral and angular. Mera Bellows provides axial and universal expansion joints, especially for the field of solar thermal energy.

Solar thermal energy systems can get very hot, as they are exposed to the sun. On the other side, in many climate zones, the surrounding temperature of the system is also getting very low (day/night, summer/winter). Thermal expansion occurs, a common problem in piping systems due to the physical properties of metal. Installers need a time-saving possibility to build up a whole Solar thermal system (on roof or solar field) that is withstanding all meteorological effects (wind, sun, rain). Mera Bellows is able to supply formed stainless steel bellows in seam-welded design for this purpose. They are manufactured with a convenient and time-saving “plug-in” system and O-Ring sealing elements on both sides. These stainless steel expansion joints are reliably connecting the solar panels and compensating movements.


Advantages of metal expansion joints manufactured by Mera Bellows

stainless steel joints - bellows expansion joints
  • High quality standards within our German groupmetal expansion joints
  • 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