AU Expansion Joint

Universal Expansion Joint

  • Simple design, Relatively low cost
  • The universal configuration can be designed with a very low lateral spring rate and high lateral
    movement capacity
  • Versatile and common throughout all industries
  • Use of tie rods contain pressure thrust. Can also include hinges or gimbals

The unrestrained EJ is appropriate for any application where pressure thrust can be handled by external anchorage. The universal unrestrained EJ is appropriate for large lateral offset requirements and wherever a low lateral offset spring rates is required.

Operating Range
  • Full vacuum to 2000 psig depending on size
  • Cryogenic to 1650°F+
  • Sizes from 1” NPS to > 240” NPS


  • 3XX Series Stainless Steel
  • Nickel Alloys
  • Carbon Steel
  • Titanium
  • Zirconium
  • Bellows may be attached or linked
    to piping flanges, pipe, or other typical industrial connections.
  • End connections may conform to standards such as ASME B16.5, ASME B36.10, or customer designed
  • Fittings generally not the same at all locations: interface connections may be as noted above. Connections within the assembly are typically to pipe.
  • Two circular metal bellows, each with 1 or more convolutions.
  • Typical dimensions of 1⁄2” ANSI NPS to 240” ID. Overall length may vary, typically within the range of 18” to 240”.
  • Bellows may include reinforcement or controlling members
  • Convolutions may be U shaped or toroidal
  • Additional accessories may be incorporated such as load bearing restraints, movement limiters, protection on devices
  • Absorbs movement, primarily perpendicular to the complete assembly (lateral) but often includes axial and/or angular movements
  • Movement amplitude varies, typically within the range of 1/2” to 20”.
  • Movement frequency may be extreme low cycle (1 per year), or high cyclic (such as vibration at 60 Hz)