Rubber expansion joints are flexible connectors

Rubber expansion joints are flexible connectors made from natural or synthetic elastomers that absorb noise, shock, vibration, physical and thermal energy. Internally reinforced with fabric or metal for strength and pressure resistance, externally reinforced with metal for movement control, they are used to absorb axial, lateral and angular movements, accommodate piping misalignment, reduce noise, and resist abrasion and chemical erosion within fluid systems.

The most important function of a rubber expansion joint is to provide flexibility that can accommodate movement in axial compression, axial extension, and lateral deflection along the longitudinal axis, as well as in the angular and torsional direction. They can be manufactured in many shapes and sizes to meet the needs of all types of applications, including water treatment plants, waster water treatment plants, raw and secondary sewage lines, air scrubber systems, centrifugal pumps, and steam turbine exhaust lines.

Compared to solid metal joints, rubber expansion joints can be more effective in accommodating significant changes in pressure. This is because, unlike metal, rubber can adjust to the change in pressure by expanding or contracting slightly, reducing the chance of warping or deformation.

There are a variety of options for expansion joints depending on their design, including molded rubber bellows, metal bellows, and reinforced fiberglass fabric. Each can be designed for a different pressure, but the choice depends on what type of application you need to address.

If you have a low-pressure application, you might be better off with a solid metal expansion joint. These are more resistant to pulsations and pressure changes, but they can also be damaged by excessive flexing or movement.

You might be able to increase the strength of a joint by adding additional bellows, but this requires some form of manual assembly and may lead to flange failure or even damage to the piping. In addition, you might not want to use a joint with metal bellows when the pressure is very high.

Some companies like to install control units on their expansion joints as back-up safety devices. These units can be a great option when piping anchors are not available or in the event of a main anchor failure.

Another way to improve the performance of a rubber expansion joint is through optimization using FEA. FEA simulates the behavior of the expansion joint under loading conditions and can identify optimal bellow shapes and required number of bellows. Using this information, TANIQ can then design and manufacture the expansion joint with smart rubber-to-cord meshing strategies that minimize the amount of reinforcement material used.

This digitized design methodology leads to increased product quality and reliability as well as reduced production time (up to 70% in some cases). In addition, this process enables the integration of a computer-controlled automatic winding machine that places the materials correctly during manufacturing.

General Rubber Corp offers rubber expansion joints that can be used in a wide range of applications. They can be designed and manufactured in a variety of styles, sizes, and materials to meet any requirement. These include spool, duct, and slip-on rubber expansion joints, and are available in a range of pressure ratings to fit various system requirements.