Types and Materials of Rubber Expansion Joints

The performance of a rubber expansion joint is crucial to the integrity and safety of a piping system. It is used to absorb movement in a pipe, relieve stress, improve thermal stability and compensate for misalignment. They are used as a component in industrial systems such as power, oil, pulp & paper and other chemical processes.

Expansion joints can be made in many different types and materials. Depending on the application, they can be manufactured in steel, stainless steel or polyurethane. Their internal tube can be made of natural rubber, synthetic rubber or a blend of both. In addition, they can be reinforced with metal rings or wire and may use PTFE (polytetrafluoroethylene) liners.

TANIQ has developed an optimized method for designing and manufacturing rubber expansion joints. This process utilizes lightweight engineering principles and in-house designed winding equipment to produce high quality expansion joints with reduced production times.

These rubber expansion joints are fabricated from an elastomeric tube reinforced with multiple plies of fabrics covering the inner tube. The fabric can be made from Nylon(r), Polyester, Aramid or Kevlar(r) and the elastomeric tube may be made from natural or synthetic rubber.

This design allows for higher pressures than a standard metal expansion joint and also eliminates sediment buildup. It also allows for a gas tight seal without the need for additional gaskets.

The bellows are fabricated from independent rubber layers and reinforcements that are vulcanized together after being molded or formed. The bellows are available in single, double and multi-arch sizes to meet the needs of a wide range of applications.

They are also available in integrally flanged designs. They are often used for ducts and fan/blower connections to add flexibility to the piping system and reduce vibration, noise and compensate for misalignment.

TANIQ has been manufacturing mandrel-built rubber expansion joints for years and has developed automation systems that produce high quality joints with minimal manual labor. The result is a reduction in production times and an increase in consistency.

Rubber flexes easily to absorb movement and withstand lateral deflection in the axial plane. This capability is beneficial for reducing wear on motive equipment such as pumps and compressors because the flexing can isolate lateral movements within the bellows.

In addition, the elasticity of rubber joints allow for a large angular range. This enables the bellows to move in a wider direction and is especially important for applications where misalignment cannot be corrected.

Because of the ability to flex, rubber expansion joints can be made from a variety of natural and synthetic elastomers and fabrics. These are able to withstand the pressures, temperatures and chemicals found in many industrial applications.

The material selection of a rubber expansion joint is very important for determining the product’s performance. The type of material, the elastomer and the fabric used to reinforce the tube can be critical in providing superior flexibility, abrasion resistance, fire resistant and durability for a specific application.

The material selection is also based on the fluids, temperatures and pressures being operated in the system. The material that best meets the specific requirements is chosen. This ensures the highest level of performance and reliability for the product.