Expansion Bellows

Expansion bellows are flexible connectors designed to protect pipework from movement, vibration, and temperature-related stress. By absorbing thermal expansion, contraction, and mechanical vibration, they help prevent damage to pumps, valves, and rigid pipe joints, reducing the risk of leaks and costly downtime.

Made from high-quality EPDM or NBR rubber and reinforced with durable metal components, these connectors provide long-lasting performance across a wide range of industrial and mechanical applications.

Key Benefits at a Glance

• Absorb thermal expansion and contraction
• Reduce vibration transfer from pumps and equipment
• Protect pipe joints and connected plant
• Support working pressures between 10–16 bar (depending on product)
• Suitable for temperatures down to –20°C
• Available in a wide range of imperial sizes
• Choice of EPDM or NBR for chemical, temperature, or media compatibility

When correctly installed and maintained, expansion bellows significantly extend the service life of pipe systems and help maintain stable, reliable operation.

While we always recommends following the manufacturer’s detailed installation instructions, the following principles offer a useful starting point:

• Confirm the selected connector meets the application's pressure, temperature, and media requirements
• Inspect the connector before installation to ensure the internal and external surfaces are undamaged
• Install the connector at its natural length - it must not be stretched or compressed to fit
• Ensure the pipework is correctly aligned; bellows are not designed to compensate for misalignment
• Check all flange faces for cleanliness and free-from burrs or sharp edges that could damage the rubber
• Flange bolts should be tightened gradually and in an opposite sequence to ensure even compression
• After installation, recheck bolt tightness after seven days
• Flexible connectors should be appropriately anchored to prevent unnecessary load on adjacent pipework and plant equipment
• Avoid painting the rubber, as this may accelerate deterioration
• Conduct periodic inspections to monitor rubber condition and bolt tightness, especially in demanding environments

Correctly installed bellows significantly enhance system longevity by absorbing vibration and thermal movement rather than transferring it into mechanical equipment or rigid joints.

A threaded EPDM bellow designed for high-pressure applications up to 16 bar. Featuring BSPT taper threaded malleable iron ends, it offers a reliable and leak-free connection for absorbing vibration, thermal movement, and mechanical stress. Suitable for temperatures between –20°C and 100°C, this is a versatile choice for compact installations where threaded joints are required.

A flexible EPDM connector supplied with carbon steel PN16 flanges. The untied design allows greater movement and flexibility within the system, making it ideal for general industrial and HVAC installations. Rated to 16 bar and operating from –20°C to 100°C, it is well suited to systems requiring maximum vibration absorption without additional movement restraint.

Similar to the PN16 untied range, but rated to 10 bar. This connector combines EPDM flexibility with PN10 carbon steel flanges, offering a dependable solution for lower-pressure systems where vibration, movement, and thermal expansion still need to be effectively managed.

Constructed from durable nitrile rubber, this connector provides excellent resistance to oils, fuels, and selected chemicals. Combined with PN16 carbon steel flanges, it is ideal for industrial environments involving hydrocarbon media. Suitable for systems up to 16 bar and temperatures between –20°C and 80°C, it offers a robust, flexible solution for more specialist applications.

This EPDM connector features integral tie rods designed to restrict excessive axial movement while still absorbing vibration and minor expansion. With PN16 flanges, a 16 bar pressure rating, and a –20°C to 100°C temperature capability, it provides controlled flexibility where system stability is essential, such as close-coupled pump installations.

A tied EPDM connector rated to 10 bar, designed for applications where axial restraint is required but full flexibility is still beneficial. The tie rods limit movement while the EPDM body absorbs vibration and temperature-induced fluctuations. Suitable for HVAC, industrial, and general process environments.