ISL - Isolated Systems Limited

Industrial Noise Vibration &
Thermal Management Solutions




Multi-Layer Seal Fabric Expansion Compensators


Multi Layer Seal Connections – All Types:

  • ISL “Multi Layer Seals”, (M.L.S.), are designed to provide: Vibration isolation, absorb expansion, reduce noise breakout and compensate for misalignment in ductwork for applications with increased operating temperatures, over and above those accommodated by our single ply Flexible Connections.
  • Standard construction M.L.S. can operate up to +550°C as standard, (depending on specific seal construction)
  • Operating Temperatures up to +1000°C can be accommodated with the inclusion of an Insulation Bolster* See Note.
  • Available in the following standard geometries:
  • “Circular Flat Flanged” (C.F.F.) - Circular with “plain ends” suitable for “Jubilee Clip” type installation.
  • “Rectangular Flat Flanged” (R.F.F.) - Square / rectangular with “plain ends” suitable for backing flat installation.
  • “Circular Angle Flanged” (C.A.F.) - Circular with flanged ends at 90 degrees to the body suitable for steel backing flanges. ** See Note
  • “Rectangular Angle Flanged” (R.A.F.) - Square or rectangular with flanged ends at 90 degrees to the body suitable for steel backing flanges. ** See Note
  • Can also be manufactured as tapering and / or transitioning from circular to rectangular geometries.
  • Can be supplied pre-punched to match clients existing ductwork flanges or “plain flanges” for drilling during installation, where specific hole centres are unknown.
  • Fire rated construction available for specific applications.
  • All related steelwork can be specified, designed and manufactured in-house, including:
  • Steel Backing Flats / Flanges, Steel Inner sleeves to protect the Flexible Connection from abrasive particles or high velocity gasses / buffeting.



* Insulation Bolsters comprise of additional layers of High Temperature Insulation Wool, encased by High Temperature Woven Glass Fabric and further protected by a layer of wire mesh.

The woven Glass Fabric can vary from 12mm thick to 150mm thick and the wire mesh can be constructed from either 304 Stainless Steel, 316 Stainless Steel or Incoloy depending on the maximum operating temperature.

**Due to potential issues with heat build-up in the corners of angular flanged Multi Layer Seal arrangements, operating temperature are limited to +550°C.  For operating conditions in excess of +550°C. Flat Flanged geometry must be specified.


Multi Layer Seal Construction / Operating Conditions / Application Summary

Plies Construction Temp (Max) Pressure (Max) Application
  1. Silicone Coated G/F
  2. Woven G/F
+250°C 254mm WG Dry Air / Gas