Fabric Expansion Joints (Non-Metallic Flue Duct)

Fabric expansion joints used for ducting systems are also known as Non-Metallic Flue Duct (NMFD) expansion joints. They were developed in the late 1960s as an alternative to metal expansion joints.
Fabric expansion joints offer more movement capability than metal expansion joints. They install and replace easier than metal and are cost less.
These joints are extremely good for large lateral and axial movements. Fabric expansion joints handle temperatures up to 2000⁰F. They are designed to last for years in rugged service conditions.
fabric flue duct expansion joint

Fabric expansion joints and non-metallic flue ducts are custom manufactured for use within ducting systems.

  • Lightweight and easy to install.
  • Tremendous thermal movement capabilities.
  • Can be patched onsite in the event of a compromise.
  • Easy to splice (if required) once installed.
  • Replacements can be made within 24 hours if required.
  • Less expensive than metallic expansion joints.
  • No size restrictions on area or face to face.
  • Available in “U-Type” and “Belted” designs and in various configurations.
  • Auxiliary equipment such as baffles, insulation pillows, back-up bars, frames, etc. are readily available.
  • We custom manufacture all fabric expansion joints for the exact application.
  • They are great against vibration and flutter which often destroys metal expansion joints.
  • NMFDs offer the lowest spring rates.

We offer rubber and fabric expansion joints for ducting systems in the following styles:

Rubber Expansion Joints to 400⁰F
Using a selection of synthetic rubbers, these expansion joints can become an extension of the ductwork needing little setback and are very resistant to abrasion. The rubber called Viton, for 400⁰F service will handle excursions to 750⁰F in the event of an unrelated equipment failure.

Teflon expansion joints to 600⁰F
Teflon expansion joints are chemically inert so they can be used in the harshest chemical environment. Additionally, Teflon expansion joints are very lightweight, easy to install and last for years if properly designed.

Composite Expansion Joints to 2000⁰F
They are constructed from multiple plies of fabric as well as Teflon gas barriers and an outside cover. Composite expansion joints offer a gas tight product for either vacuum or positive pressure applications.

Convoluted Expansion Joints
Although NMFDs offer great movement abilities versus metal expansion joints, convoluted expansion joints offer huge axial and lateral movement relief. These expansion joints can contain single or multiple convolutions depending upon the need.

Request a quote for Fabric Expansion Joints

Customers can request a quote by downloading the Non-Metallic Flue Duct RFQ form and attaching it to our contact form.