Fabric Expansion Joint are suited for gaseous media, such as air, exhaust gases and solvent fumes, as well as for operation below the dew point (also involving substances with a certain concentration of acids), as well as with abrasive enriched gases (e.g. coal or cement dust).

Due to their modular design, fabric expansion joints can especially well adjust to different requirements (e.g. critical sealing requirements, frequent

temperature and pressure variations) and therefore cover a very wide spectrum of applications. The high quality materials as well as the technical

experience in designing and manufacturing vouch for the high quality and long lifetime of the fabric expansion joints of High Hope.

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.

Material

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

a.    Temperature and corrosion resistant insulating fabrics for temperature decrease;

b.    Gas impermeable films, foils or composites of materials as Teflon® (Polytetrafluorethylene, PTFE), Silicone, Hypalon, Inconel or aluminium;

c.    UV resistant and water resistant materials for reasons of weather protection;

d.    Support layers such as glass or polyester fabric and the like for pressure absorption;

e.    Mechanically stable layers such as wire mesh and silicone film as abrasion protection.