Fabric Expansion Joints
Another expertise of REX is to manufacture Fabric Expansion joints (bellows) of virtually any size & shape, from a range of proven standard constructions or designed especially for defined application.
It is essential that all the relevant parameters and conditions affecting Expansion Joints are taken into account. REX has three basic types of Multi-Layer construction to meet the various needs of our customers
Type 1 :
for clean air systems: ranging from simple air intake/exhaust on fans and blowers to high temperature air discharge from heaters.
Type 2 :
for gas with low acid content: used on Gas Turbine Exhaust and less severe flue gas systems.
Type 3 :
for gas with high acid content: for use in environments where the flue gas contains acids at temperature or acids that can form due to condensation at shut down.
Acid barriers are either PTFE impregnated glass cloth or PTFE foil thermally welded to ensure tight seal.
Multi-layer fabric temperature range is from -50°C and 1090°C with a standard pressure range of ± 120" W.G
An important difference in the REX Multi-Layer Fabric is that we do not rely on an insulation pillow to reduce the temperature in contact with the element.
The Multi-Layer Fabric is always designed to withstand the temperature regardless of secondary insulation pillow.
Many competitive designs rely on this insulation pillow for primary protection of their element with disastrous results after several temperature cycles.
- Accommodate relatively large movements and even some misalignment of flanges.
- Light weight & easy to install and with the addition of
- Internal insulation bolsters have good acoustic properties.
Fabric expansion joints can be supplied fully assembled and fitted to support steelwork ready for insertion into ductwork.
For retrofit applications, we can supply as factory joined or open for on-site joining where access is limited.
Design of Multi Layer Elements
The design is based on the fabric element's ability to withstand the media temperature.
Multi-layer fabrics are offered in three basic styles: Clamp-on, Belt-Type and Flange Type.
The five basic style numbers shown below meet all positive and negative pressure applications.
Profile 1 Suitable only for applications operating under negative pressure. But will accommodate relatively large movements.
Profile 2 Suitable only for applications operating under positive pressure. But will accommodate relatively large movements.
Profile 3 Used when flange depth is limited and is suitable only for applications operating under positive pressure.
Profile 4 Suitable for both +ve & -ve pressures. If used with a suitable insulation bolster, will provide resistance to highest temperatures.
Profile 5 Suitable for operating under both positive and negative pressures.Mostly for applications with small flanges and little movement.
Temp. capabilities range from -50° C - +1260 °C and pressure range from -50kPa to +50kPa.
The sectional view of a standard Expansion Joint engineered approach to Multi-Layer Fabrics.