Types and Uses of Rubber Expansion Joints in Pipeping Systems
- Written by: Peter Harrison
- Category: General
- Published: December 20, 2022
Rubber expansion joints are made of elastomeric tube and reinforced with fabric or metal for pressure resistance and movement control. They offer a wide range of benefits including isolation of vibration, noise reduction and resistance to chemical erosion. They can also be manufactured to be installed in a variety of conditions, from hot to cold, and in abrasive or chemically corrosive environments.
There are several different types of rubber expansion joints, and they can be used in a variety of different piping applications. For example, a sponge rubber expansion joint is frequently used in sewage treatment plants because of its excellent recovery ability after compression. They are also used for isolation purposes around drains and supporting pillars. They are often used on bridge structures because they offer a high level of resiliency. They are also widely used in lamp posts, because of their superior durability.
The best material for a rubber expansion joint is EPDM. This material has a higher resistance to temperature than Neoprene, and it has better physical properties. It is recommended for use in applications involving hot air or abrasive liquids. For other applications, such as raw sewage, the ideal material is Nitrile.
The rubber bellow of the expansion joint is usually vulcanized after molding. The elastomer is then reinforced with fabrics or wire to form the body of the joint. The fabric is typically supported by solid rings or wire embedded in the body of the expansion joint. These flange rings can be either full face or spool arch, and they are available in single arch or multiple arches. The rubber expansion joint spool arch type is also offered with Fluoroplastic liners, which are resistant to most chemicals.
The metal reinforcing rings are typically made of stainless steel or epoxy coated steel. These rings are used to connect the rubber flanges of an expansion joint to a mating piping system flange. They are available in many different sizes and can be ordered to meet customer requirements.
When installing a rubber expansion joint, be sure to follow the manufacturer’s instructions to ensure that the flanges do not leak. It is also important to allow sufficient space for the expansion joint to expand or contract. If the flanges are not seated tightly into the piping, they may overexpand, which will cause damage to the joint and equipment. A common failure site is the bolts. It is important to retighten the bolts after the initial installation.
There are also different styles of rubber expansion joints. The most common are the spool, spherical and IIR varieties. Each style has its own advantages and disadvantages. While the spool joint is designed for short lengths, the spherical and IIR types are designed for longer lengths. It is important to determine which type of joint is most appropriate for your project. The spherical and IIR models are suited for vertical pipe applications, while the spool design is more commonly used for horizontal piping systems.
Rubber and metal expansion joints are similar in their axial plane motion capabilities, but rubber joints have better lateral motion capacities. They are also less susceptible to plasticization, which can result in fatigue breakdown.
