Expansion joint rubber is a lightweight and durable engineering product that can be installed in many different systems. They are also flexible and able to absorb large deformations. They are widely used in industries and buildings that require large angular movements. The material can be made from many different elastomers. The best choice for chemical and hot air applications is EPDM. Other common materials are Hypalon, Neoprene and PTFE. However, different elastomers have differing compatibility to chemicals and abrasive slurries. Therefore, it is important to understand the specific characteristics of the materials and how they will perform.
Typically, rubber expansion joints are installed in a wide range of temperatures and media. The material can be reinforced with a control rod assembly to prevent excessive movement. Alternatively, an epoxy filler can be added for additional protection. They can be supplied with fabric flanges and retaining rings. They are also available in a variety of pressures and temperatures. They have a good acoustical and vibration isolation properties. In addition, they provide long maintenance free service.
The expansion joint rubber two main types of expansion joint are hand-built and mandrel-built. Hand-built rubber expansion joints have a wider arch. They are made of pure or heat-resistant synthetic elastomers. The elastomers are then vulcanized after they have been placed in the mold. A series of plies of fabric are then applied to the elastomers. The lining tube is then pressurized. Depending on the application, a white PTFE liner may be added.
Mandrel-built rubber expansion joints are produced in either one or four arches. They are made of natural or synthetic rubber. The material can be reinforced with wire or solid rings. They are then positioned on a cylindrical mandrel. In contrast to hand-built expansion joints, the flange rings are not embedded in the rubber. The wall thickness is typically between 12mm and 25mm.
The style FTF joint is perfect for large lateral or axial movements. It is made from heat resistant synthetic elastomers and is reinforced by wire or solid rings. These types of expansion joints are ideal for chemical, power generation, and shipbuilding industries.
Rubber expansion joints can be used in a wide range of temperature and pressure conditions. They are suitable for abrasive materials, like sewage, as well as corrosive environments. They are designed to be installed close to the main anchor point. Unlike metal, rubber expansion joints can accommodate bends. They are also a better solution for situations where vibrations are required to be absorbed.
If a rubber joint fails, it could be due to damage or temperature. A common failure site is a loose bolt. Another type is a crack or abrasion. A proper inspection of the exterior and interior of the expansion joint should be performed before installation. It is also recommended to have a secondary seal of elastomeric epoxy. The epoxy should form a non-slump mortar consistency. Ensure that the bolts are tightened after installation. It is recommended that a control unit is also installed to provide backup safety.