Flue Gas Expansion Joints

Specifications

Our flue gas expansion joints (compensators) are manufactured in two main types to suit operational requirements and flue gas system design:

Circular Cross-Section Axial Expansion Joint – This type features a roll-formed bellows designed to absorb axial movements. Structure:
- Bellows: 0.6 mm thick stainless steel corrugated bellows
- Thermal protection liner: 2 mm thick stainless or heat-resistant steel plates on both sides, in a dual sliding configuration
- Connection: Provided with weld-on ends or as a loose-flange design. For the loose flange option, flared tube ends and matching counter flanges are supplied if needed.
Usage: This expansion joint is suitable for high-temperature flue gas systems where axial thermal expansion must be accommodated.
Square Cross-Section Lens Expansion Joint – For square or rectangular ducts, a lens expansion joint is used. It consists of a deep-drawn "lens" shaped element that absorbs forces from thermal expansion and pressure fluctuations. Structure:
- Lens (rim): Deep-drawn 2 mm thick stainless or heat-resistant steel plate
- Thermal protection liner: Dual 2 mm thick plates on both sides, sliding into each other (double-wall liner)
- Connection: Available with weld-on ends or as a loose-flange design, with flared ends and counter flanges provided if required.
Usage: This design ensures proper movement compensation for square duct sections while minimizing structural stress and guaranteeing long-term operational safety.

Selecting the appropriate expansion joint type depends on the geometry of the flue gas system, operating temperature, and mechanical loads involved.

Flue gas expansion joints are crucial elements in flue gas pipe networks that allow for the compensation of thermal expansion, pressure changes, and mechanical vibrations. They relieve mechanical stress on piping, prevent stress concentrations, and contribute to the system's operational safety and extended service life.

We manufacture each expansion joint customized to the specific operating conditions, considering connection type, operating temperature, pressure, and flue gas composition. Our expansion joints can be applied in boilers, gas engine exhaust systems, gas turbines, and other industrial flue gas systems where pipeline movement compensation is required.