Understanding The Different Types Of Expansion Joints

Understanding The Different Types Of Expansion Joints

The value of expansion joints becomes clear to everyone during those hot summer days when structures tend to change their dimensions and warp because of changes in the temperature. Relieving these thermal stresses is precisely what expansion joints are made for. Ducting and piping are applications where thermal pressures are especially concerning since you cannot tolerate any uncontrollable warping in your pipelines. Below, we outline the various types of expansion joints instrumental in these applications, as well as many other process systems.


1. Single expansion joints

Single expansion joints are mid-structure elements that eliminate or at least minimise the tendency of structures to become deformed under thermal load, i.e. contract or expand when temperature fluctuations occur too quickly. Furthermore, this single joint serves as protection from axial vibration forces that may cause substantial axial movement along the length of the structure that the joint is supposed to hold together. Proper alignment is critical for single expansion joints to effectively absorb motion in three directions — lateral, angular, and axial.


2. Hinged expansion joints

Hinged expansion joints perform well in applications requiring greater restriction in the pipe or beam. This joint is designed to limit angular rotation in every plane save for one. Its physical difference from other types of joints is evident in its hinged plates located at the ends of the joint, which reflect the plane where angular rotation is desired. Since only angular rotation is permitted, hinged expansion joints can handle extreme forces and loads by absorbing and transferring them to the angular plane.


3. Toroidal expansion joints

At times, the pressures applied to a connected structure are too extreme, and the variations in temperature are so sudden that both single and double joints are insufficient. These situations require the use of toroidal expansion joints. Their geometry is designed in such a way that there can be variations in the wall thickness to manage various operating stresses stemming from the pressure on the structure held by the joint. These joints are mainly used in applications involving heat exchange.


4. Fabric expansion joints

Fabric expansion joints are the first to feature a rectangular makeup instead of circular geometry. They are mainly used to support virtually all applications employing cross-sectional ducting. Fabric expansion joints are strong and sturdy and can generally be tailor-made for specific applications for guaranteed longevity and reliability.


5. Gimbal expansion joints

The gimbal joint is less conservative in contrast to the more restrictive design of the hinged expansion joint. It allows for angular rotation in all planes, which means it can also handle stresses from any plane. Due to its exceptional load capacity and ability to deflect pressures, engineers often favoured it in facilitating placing pipe supports.


6. Universal expansion joints

The purpose and scope of these joints are evident in their name. A closer look into their construction shows that they are double-jointed connectors that are not physically connected to the structure. This lets them absorb axial, angular, and lateral stresses that single expansion joints cannot deflect. As they can absorb thermal pressure from all planes, they have become a staple in steam distribution systems wherein their utility generates significant cost savings.


7. Pressure-balanced expansion joints

Pressure-balanced joints play a vital role in the proper operation of manufacturing equipment, pipe anchors, and turbines because they can deflect excess pressure from these elements. These joints are especially useful in segments of long pipelines where the direction changes.



Expansion joints come in various forms, shapes, and materials to serve many different purposes across a wide range of industries. But regardless of your application, the quality of the expansion joints you need ultimately comes down to choosing the right manufacturer.

If you need high-quality expansion joints made from various materials like metal and fabric, Pharmchem Engineering has what you need! Backed by our decade of quality experience, you can trust our wide range of industrial engineering supplies such as expansion joints, anti-vibration mounts, pipe pigging equipment and more to meet your requirements and expectations. Do not hesitate to contact us today for solutions according to your needs.