The reduction in the breach opening along the axis of the duct. This is usually a result of thermal expansion of the ducting.
![Fabric Expansion Joint Axial Compression](https://devptp.usbellows.com/wp-content/uploads/2019/03/axial-compression.jpg)
The reduction in the breach opening along the axis of the duct. This is usually a result of thermal expansion of the ducting.