Fabric Convoluted

Fabric Convoluted Expansion Joints are ideal for very high or extreme movements, axially or laterally, in complex ductwork. They can handle up to +/- 18” of movement axially for example. Hunter can supply convoluted, accordion style Flex elements only or we can supply complete shop assembled units with all steelwork and shipping Bars included. Knocked down component supply is also available.


  • Very, very high movements, axial or lateral as high as +/- 18” inches.
  • Single, Double, Triple, a Dozen, or Multiple Convolutions.
  • Ideal for complex ducting systems with high temperatures.
  • Internal and/or External Support Rings for Horizontal or Vertical Ducts

Material Types:

  • Neoprene and EPDM to 300 F
  • Silicone to 500 F
  • Teflon & Teflon Composites to 600 F
  • Composites or Multi-Layers to 1200 F & 1500 F +
  • Fiberglass, Ceramic, Silica, Stainless Wire Mesh

Steelwork Accessories:

  • Clamping Bars – aka – Back Up Bars, Retaining Rings – CS or SS
  • Mounting Frames or Angles – Carbon Steel, Stainless Steel, Alloy
  • Flow Liners or Baffles – Tapered, Single or Double Break, Telescoping
  • Shipping Bars & Extra Mating Flanges
  • Shop Assembly for One Piece Installs


  • Used where thermal movements in ductwork are unusually large
  • Used where Air or Gas stream is generally clean
  • May be clamped or flange bolted into place
  • Stainless Steel or Carbon Steel Support Rings