General information

Innoway fabric expansion joints can be used for compensation of axial, angular and lateral expansion movements in pipes. Additional allowable movements are also admissible due to the high flexibility of the fabric and the complex shape of the fabric expansion joints. The large reaction and adjusting forces that are usual for metallic expansion joints can also be neglected in the planning, with minimal duct impact being resulted from fabric solutions. In case of large lateral movements there is the advantage against metallic expansion joints that the compensation performance can be accomplished in a much more compact design. For systems with vibration and oscillation movements special designs are available.

Geometry of fabric expansion joints

Innoway fabric expansion joints are available in any geometric shape (round, square, oval) and in any size. A metal frame, the fabric and if necessary insulation bolsters, together with flow plates and specially shaped convectors form the construction of the fabric expansion joint system. The metal frame serves to fix the fabric and the expansion joint to the duct. The fabric expansion joint takes up movements as well as mechanical and acoustic vibrations. It usually consists of several layers. Each fulfils certain requirements, e.g. tightness, absorption of pressure shocks, insulation and temperature decrease as well as mechanical protection. Depending on the application and temperature additional insulation bolsters are used. Disturbing turbulences are minimised by flow plates and the expansion joint is protected from flow and high velocity. The convectors dissipate the heat to the ambiance to ensure that the maximum operating temperature at the sealing layers will not be exceeded while allowing a minimum temperature drop at the steel parts.


Usually the expansion joint is a multi-layer design. The different layers consist of:

  • Temperature and corrosion resistant insulating fabrics for temperature decrease;
  • Gas impermeable films, foils or composites of materials as Teflon® (Polytetrafluorethylene, PTFE), Silicone,
  • Hypalon, Inconel or aluminium;
  • UV resistant and water resistant materials for reasons of weather protection;
  • Support layers such as glass or polyester fabric and the like for pressure absorption;
  • Mechanically stable layers such as wire mesh and silicone film as abrasion protection.