The presence of vibration in fluid transmission lines and systems is inevitable. These vibrations occur for various reasons. Fluid temperature changes, design working environment temperature changes, continuous vibration caused by unwanted movements of mechanical devices in the system (pumps, compressors, fans, turbines, etc.), or external causes such as wind, earthquakes, structural settlement, etc. The reason is that various Expansion Joints are used to absorb these unwanted movements and prevent their transfer and damage to the system and premature wear of the pipeline and other parts, depending on the fluid temperature, pressure, working environment, & etc.
Today, various types of Expansion joints are used in industries, depending on the working conditions; very diverse types are used in a general classification, divided into three main groups:
• Metal Expansion Joints
• Rubber Expansion Joints
• Fabric Expansion Joints
The choice of each type of expansion joint generally depends on the amount of working pressure as well as the working temperature entering the inner wall of the pipe, and according to the nominal capacity to withstand the temperature and pressure of metal, fabric, or rubber materials, the type of expansion joint is chosen is limited.
Fabric Expansion Joints
Fabric expansion joints are another type of expansion joint that can be designed for ducting and piping systems. These expansions are widely used in most industries, including oil, petrochemical, refinery, steel, and power plant industries. Fabric expansion joints with proper design have a very high ability to withstand high temperatures and corrosive gases. Compared to metal and rubber types, their most important advantage is that they are cheaper, and their design and production time are faster.
The expansion structure of the fabric joints depends on the location, temperature, and working pressure, and they are layered from the inner side, which is exposed to passing gases, to the outer side, respectively. Each of the used layers has a specific mechanical, temperature, and corrosion resistance which according to the factors of working pressure, ambient temperature, and the corrosiveness of passing gases in working conditions (dry or wet), design, produce, and install on-site.
Other kinds of expansion joints, such as metal and rubber types, have different categories according to the section of the pipe or duct (circular and rectangular, connection type, flange type or metal strip, etc.). Therefore, environmental working conditions and installation location play a decisive role in the design and production of expansion joints.