Flexible fabric expansion joints provide for movement due to thermal expansion and vibration within a duct system. They are commonly used in low-pressure ducting systems, including air handling systems, exhaust systems, and flue gas systems.
Construction and Materials
These expansion joints are also regarded as multi-layered expansion joints, as several layers of technical textiles and elastomers assist in the manufacture of fabric expansion joints. They work in synchronisation to provide strength, flexibility, and protection/performance for the particular component they will be installed on.
Layered Fabric Design
Some common materials used to manufacture fabric expansion joints
are fibreglass, silica fabric, ceramic cloth, and various types of coatings, including silicone, PTFE (Teflon®), and neoprene. Each of these materials is selected to match specific operating, environmental, and/or specific conditions (temperature, pressure, or chemical exposure).
Types of Movements Accommodated
- An axial movement is defined by the length or the increase and decrease of the alloy to heat.
- Lateral movement is caused by the shifting of alignments (side to side).
- Angular movement is caused by system dynamics in the form of bending or rotation around an axis.
Industrial Applications
- Power Plants and Flue Gas Systems
Fabric expansion joints are essential in flue ducting systems where high temperatures and corrosive gases are present.
- Cement and Steel Industries
They are used to handle hot gases, dust, and abrasive materials in processing plants.
- HVAC and Ventilation Systems
In commercial and industrial buildings, they help manage airflow and reduce vibration.
Key Advantages
- Versatile
Fabric expansion joints allow for significant movement and are, therefore, less likely to put load/strain on the connected equipment.
- Protect against Corrosion
Some coatings (for example, PTFE) will make it possible for the fabric expansion joint to endure aggressive chemicals and gases.
- Dampen Vibration & Noise
They serve as dampers and contribute to system stability while reducing the amount of noise during operations.
- Lightweight & Easy to Install
Due to their lightweight nature, fabric expansion joints are easier to handle when transporting and installing than metallic expansion joints.
- Custom Engineering
Expansion joint manufacturers provide custom-engineered joints to suit the size of the duct, the temperature range, the pressure range, and the type of medium being moved through it.
6. Additional Features
These expansion joints have additional features such as insulation pillows, liners, and gas seals, which increase the performance and life span of the joint.
- Installation and Maintenance
The long life of the fabric expansion joint will depend on the accurate alignment of the joint and the adherence to the installation instructions provided by the factory where it was manufactured.
- Routine Inspections
Regularly checking for wear, damage from chemicals, etc., can help to prevent unexpected failures in the fabric expansion joints.
Limitations of Fabric Expansion Joints
Suitable for low-pressure industrial applications
These expansion joints are not suitable for higher-pressure applications
Sensitive to material changes
The performance of a fabric expansion joint can vary greatly depending on the materials selected for that application.
Wrapping Up
Fabric expansion joints are an effective alternative to mechanical means of controlling thermal expansion, vibration, and movement in ductwork systems. Properly designed, installed, and maintained, these systems provide considerably increased performance levels and useful life to ductworks in many industrial applications.
AFS Joints for Custom Engineered Expansion Joints
Advanced Flexible Systems is engaged in providing reliable and durable custom expansion joints for diverse applications and industries. Whether you are looking for belt expansion joints, fluoroelastomer expansion joints or fabric expansion joints, AFS Joints is a leading designer and manufacturer of dependable, high-quality expansion joints for all markets.