How to Design a Rubber Expansion Joint

When designing a rubber expansion joint, the design and production process must optimize the properties of the materials used. High-end expansion joints are mandrel-built, and reinforcement cords are embedded in the rubber. They are then applied as sheets, typically in pairs with the cord angles facing opposite directions. Once adhered, the reinforced materials are cut and folded under the flanges.

Fabric reinforcement

Fabric reinforcement for a rubber expansion joint can improve the joint’s strength and reliability. Fabric reinforcements can be used in both high-pressure and low-pressure applications. The outer layer of the joint should be compatible with its surroundings, and it should be made from materials that will resist corrosion and oils.

High-molecular-weight polymer chains

In polymer systems, high-molecular-weight polymer chains have several advantages over low-molecular-weight polymers. These chains have better impact resistance and are able to withstand stresses more easily. However, they have lower flexibility and strength due to their lack of chain entanglement.

Synthetic rubber

Synthetic rubber expansion joints are used in a wide variety of industrial applications, including building structures. They are highly durable and cost-effective. Synthetic rubber is used in these applications due to its ability to resist temperature extremes and chemical resistance.

Light weight

If your construction project calls for an expansion joint, you should look for one made of rubber. They reduce heat loss and offer longer maintenance free service. They can be made with nylon fabric-reinforced neoprene bodies or forged carbon steel flanges.

Resistance to abrasion

TheĀ abrasion resistance of expansion joints is an important consideration for many applications. Abrasion resistance is determined by using a method known as the Pico Abrasion Index (PAI). The method, developed by the American Society for Testing and Materials, involves abrading a rubber specimen by rotating a drum containing coarse sandpaper. The higher the percentage of material worn away, the poorer the elastomer’s resistance to wear. These tests provide valuable information on the durability of an expansion joint, resulting in longer life and improved system reliability.


Rubber expansion joints are used in a variety of applications. They are often used in power generation plants to control the expansion of pipes that move fluid. Coal-fired, hydroelectric and nuclear-heated facilities are among the industries where they are used. In these facilities, there are many different kinds of fluid pipe systems.