Size, Pressure & Special Routing · Size, Pressure & Special Routing
Duct expansion joint in long run
Thermal movement
ConnectionListed expansion joint
SupportFixed anchors + guides
Before you start
- Confirm calculated movement, expansion-joint model, neutral length, fixed anchors, guides, movement direction, temperature range, and support load.
- Inspect the flexible element, frames, shipping bars, labels, and stops.
- Verify the joint is not intended to carry duct weight, twist, or misalignment.
- Coordinate installation temperature and neutral position.
Tools and materials
Listed expansion joint, fixed anchors, guides, independent supports, approved flange or welded connection components, level, tape, manufacturer instructions, and movement markers.
Lay it out
- Mark fixed points, guides, and movement direction.
- Set the neutral joint length for installation conditions.
- Keep the joint away from unintended side load.
Set and support it
- Install anchors and guides before releasing the joint.
- Support both duct runs independently.
- Hold the joint square and neutral.
Make the connection
- 1
Verify the movement calculation and anchor plan.
- 2
Set the expansion joint at the required neutral length.
- 3
Connect the first side without twist.
- 4
Align and connect the second side.
- 5
Complete fixed anchors and guides.
- 6
Remove shipping restraints only when instructed.
- 7
Mark and inspect the movement direction.
Check the install
- The joint sits at the correct neutral length.
- Anchors and guides match the movement plan.
- The element carries no weight or twist.
- Movement direction is clear.
- No shipping restraint remains unintentionally.
Common mistakes
- Installing without fixed anchors.
- Using the joint to correct misalignment.
- Removing shipping bars too early.
- Setting the wrong neutral length.
Stop and ask
Stop if the movement calculation, neutral length, anchor plan, guide layout, or installation-temperature condition is missing.