1. Definition:

A fabric expansion joint is flexible connector, fabricated of elastomers, fabrics, insulation materials and PTFE, depending on customers’ requirements, designed to provide stress relief and seal in gaseous media in piping systems. It performs a function of compensating for duct misalignment and duct thermal growth, absorbing large movements than metal expansion joint, and doing so without spring loads. CDI is now able to offer better sealed fabric expansion joints aim to the use of toxic and hazardous gases.

2. Principal uses:
It is found wherever there is a need to convey hot media in low pressure applications such as "in flowing air" and "out flowing gas" in large combustion processes.

3. Features:

3.1 Flexibility:
The fabric bellows, made of a flexible sheet material, can accommodate complex displacements caused by thermal changes and movements, such as vertical dislocation, twist and misalignment.

3.2 Chemical resistance:
The fabric bellows, coating with Fluoro material (PTFE), can withstand exhaust gas or other corrosive gases, such as SOx, NOx.

3.3 Displacement accommodation:
The capacity to accommodate more displacements than metallic expansion joint can reduce the installation space (face-to-face distance). The standard installation space is 300 mm. This can also reduce the number of joints.

3.4 Small reaction force:
Compared with metallic expansion joint, it has smaller reaction forces to work on ducts and piping, so that it gives more freedom to duct design.

3.5 Reduce vibration:
Normal mechanical equipment vibration can be reduced through fabric expansion joint.

3.6 Various forms:
Be available in various forms, such as round, square, tapered (with different bores) or large bore.

4. Advantages:

4.1 Absorb simultaneous movements easily in more than one plane:
Fabric expansion joints are allowed to accommodate composite movements in fewer and simpler units.

4.2 Very low forces required to move the expansion joint:
The low spring rate enables their uses to isolate stresses on equipment.

4.3 Corrosion resistant materials of construction:
Fabric materials enable the use in aggressive chemical conditions.

4.4 Noise and vibration resistance:
A fabric expansion joint provides a high degree of noise isolation and vibration damping.

4.5 Minimal replacement cost:
A fabric expansion joint can be replaced by simply and economically.