Expansion joints are crucial components of various industrial applications. They play a critical role in ensuring integrity of the structure and maintaining safety and efficiency of the system. Lets delve deeper into unique characteristics of expansion joints and their different types.
What are expansion joints?
An expansion joint is a flexible component installed in a piping system. Its primary goal is to absorb movement caused by thermal expansion, contraction, vibration and pressure fluctuations. When pipes transport different fluids at varying temperatures, these fluids usually expand or contract the pipe. These connectors help in absorbing these movements as well as keeping the system safe and efficient.
Expansion joints are used in various industrial applications. They reduce strains on pipes and equipment and extend the lifespan of the system. By removing fixed points and guides, expansion joints allow engineers to increase flexibility in pipe designs while minimising expense. Their unique design incorporates a variety of components such as bellows, welding ends, flanges, hinges, and tie rods. When you hire experts, they work along with you in designing custom expansion joints based on your specific application requirements.
Characteristics of expansion joints
- Expansion joints enable thermal contraction and expansion without allowing stresses into the elements.
- They are primarily designed to safely absorb expansion and contraction of several construction materials, absorb vibrations, and permit soil movements due to seismic activity or ground settlement.
- The expansion joints are normally installed between sections of bridges, paving slabs, railway tracks, and piping systems.
Different types of expansion joints
Expansion joints can be widely categorised as metallic and non-metallic expansion joints based on whether they are made up of metals or other materials such as fabric, rubber etc. The application for which it is used plays a key role in determining the right material of an expansion joint. Some of the common types of expansion joints used in most industries are as follows:
- Elastomeric expansion joints
Elastomer-based expansion joints can be regarded as unsung heroes of any infrastructure. These expansion joints work as mechanical shock absorbers, expanding and contracting to accommodate movement and providing a robust sealing solution for both environmental and operational challenges. It is imperative for engineers, architects and project managers to have an understanding of elastomeric joints to attain excellence in their designs and structures. The elasticity of the elastomer is a key feature of an expansion joint. These expansion joints have the unique capability to return to their original shape after being stressed. It ensures that the expansion joint is able to endure repeated movements without degradation. Its resilience also ensures long-term durability. Elastomeric expansion joints are crafted to withstand the rigours of their environments, combating corrosion, temperature changes, and oxidative ageing with impressive fortitude.
- High-pressure expansion joints
High-pressure expansion joints are used in case of high internal pressures and/or for balancing the movement among all the corrugations. It involves the use of reinforcement or pressure-balancing rings installed around the outside of the convolution. It helps in preventing the bellows from being forced out of shape due to the high pressures. The main goal of these devices is to reinforce the bellows against internal pressure and equalise the movement among all the corrugations. Equalising and reinforcing rings are made from carbon steel, stainless steel or other suitable alloys. Reinforcing rings are typically in cross section,, and equalising rings are generally fabricated from tubing or solid round bars of carbon steel, stainless steel, or other suitable alloys. Bellows and reinforcing rings can be incorporated to any type of Expansion Joint (Axial, Lateral, Angular, etc.)
- Fluoropolymer expansion joints
Fluoropolymer expansion joints are fabricated from fluoropolymer materials like PTFE (Teflon), FEP, or PFA. These expansion joints are designed for high chemical resistance and non-stick performance in corrosive environments (acids, solvents, etc.). they are used in such as chemical processing, scrubbers, chlorine and acid lines, and pharmaceutical or food industries.
Things to consider for choosing the apporpriate material
The choice of material varied according to industrial application for which it is used. Here are the common considerations for choosing an appropriate material for expansion joint
- Material Compatibility – Not all expansion joints are compatible to all applications. The choice of material plays a key role in determining material compatability. The chosen material must be suitable for the surrounding environment of the application (e.g., chemical resistance, heat resistance).
- Movement Capacity – One must also consider the amount and type of movement required to accommodate by the expansion joint
- Pressure and Temperature Ratings – Your chosen expansion joint should be able to withstand the operational conditions of your system.
- Installation Requirements – Different expansion joints require specific installation methods to perform effectively. It is important to understand the installation requirements to ensure performance and longevity of the expansion joint. One should consider the instructional manual and guidance from expansion joint suppliers to ensure smooth installation of the expansion joints.
