Fabric Expansion Joints for Industrial Exhaust, Hot Gas & Ducting Systems

Temperature changes can cause significant dimensional changes in piping and ducting systems. Additional movement may result from vibration, displacement, installation tolerances and movement of connected equipment.

A correctly engineered fabric expansion joint can accommodate different types of movement within a single flexible component.

These include axial movement along the longitudinal axis, lateral movement transverse to the axis and angular movement resulting from angular displacement between connected components.

One of the key advantages of non-metallic expansion joints is their high degree of flexibility. This allows combined movements with comparatively low reaction forces. The permissible movement capability is defined individually according to the geometry and operating conditions of each application.

A fabric expansion joint is more than a single piece of fabric. Particularly in demanding high-temperature applications, the required performance is achieved through a carefully engineered single- or multi-layer construction.

Depending on the application, temperature-resistant E-glass, high-temperature glass or silica fabrics can be combined with functional layers and coatings made from materials such as PTFE, silicone and other application-specific materials.

Load-bearing layers absorb mechanical stresses, sealing layers are selected according to the respective process medium, and additional insulation layers reduce the thermal load on outer functional layers when exposed to high gas temperatures.

The complete construction can therefore be tailored to dry or wet media, temperature, chemical exposure, weather conditions, movement requirements and the specific installation environment.

In exhaust gas, flue gas and hot air systems, process temperatures can be significantly higher than the permissible operating temperature of individual sealing or coating materials.

For these applications, we engineer multi-layer high-temperature fabric expansion joints. Temperature-resistant fabrics and insulation layers are combined so that the thermal load within the expansion joint construction can be reduced in a controlled manner.

Depending on construction, process medium and operating conditions, applications with process temperatures up to approx. 900 °C can be realised.

Maximum temperature alone is not sufficient for correct material selection. Flow velocity, pressure, moisture, chemical composition, dust loading and possible condensation must also be considered when engineering the expansion joint.

Industrial air, exhaust gas and ducting systems rarely follow uniform standard dimensions. We therefore manufacture round, rectangular and custom-shaped fabric expansion joints according to the actual installation geometry.

Depending on the construction and maintenance concept, attachment can be realised using flanges, clamping bars, clamping bands or application-specific fastening systems.

At high flow velocities or with abrasive and particle-laden media, an additional internal flow liner or protective liner may be advisable. This reduces direct exposure of the flexible material to the process flow and is considered during the project-specific design.

Existing installations can also be accommodated. Dimensions, connection geometry and available installation space provide the basis for engineering a replacement or newly designed expansion joint.

The performance of a fabric expansion joint is not determined by the fabric alone. The decisive factor is whether material construction and design match the actual operating conditions.

Our engineering process is based primarily on temperature, process medium, operating pressure, required movement capability and connection geometry.

We also consider factors such as flow velocity, dust and particle loading, moisture, condensation, chemical exposure, vibration, and whether the system is installed indoors or outdoors.

The more complete the available operating data, the more precisely the material construction and expansion joint design can be matched to the application. Existing drawings, photographs or specifications of an existing expansion joint can also serve as a basis for engineering.