Lateral Expansion Joints and Their Variants

Expansion Joints are important components that absorb movements created due to shock, vibration or heat inducted expansion-contraction. These industrial parts also known as bellows are used in almost all core industries for their movement absorbing capabilities. While many varieties of expansion joints are used for various purposes, lateral expansion joints are, till date, one of the widely used designs.

Lateral expansion joints are one of major variants of metal bellows or expansion joints. Widely used in various industries, these expansion joints are generally used to absorb lateral movement along the pipe systems. The main components of a lateral expansion joint are the tie rods or swivel tensions, central spool and the bellows units.

How does it Work?

Lateral expansion joints employ the working principle of hinged bellows. Utilising the capacity of angular movement, these metallic expansion joints provide excellent movement absorption in any pipe system that changes direction.

These expansion joints are capable of eliminating huge pressure thrust by employing two bellows units joined with a pipe called central spool. The tie rods or swivel tensions are used to attach the outer ends of the bellows to prevent any axial movement. This design of a lateral expansion joint allows it to absorb any level of pressure thrusts. Although tie rods are generally used for low to medium pressure thrust systems, one would require using swivel tensions for handling huge pressure thrusts.

The length of the central spool is vital here. As the movement capacity of the bellows increases with the increase in the distance between two bellows units, to handle larger amount of movement and pressure you’ll require a larger central spool. Similarly to handle low to medium movement you can employ a smaller central spool.

Lateral Expansion Joints and Their Variants


These bellows are widely used across many industries for their capability of handling huge pressure. To put it in a simple term, lateral expansion joints are used in any high pressure pipe system that changes directions especially used in the Z-shaped systems.

Widely used in many industries, these metal bellows or expansion joints owe their popularity to the following features:

  • Capacity to handle large amount of pressure from any direction in one plane makes it perfect for a Z shaped system;
  • Ability to absorb pressure thrusts effectively;
  • Simple design
  • Minimal guiding requirements;

Variants of Lateral Expansion Joints:

Due to their simple design, it is possible to create many variants of lateral expansion joints for various uses and many companies alter the designs according to the requirement of their clients. Here is a brief detail of commonly used variants.

Connection Parts:

These are simple bellows equipped with fixed flanges, weld ends or swivel flanges or even a combination of these components according to the user specific requirements.

Single/Double Bellows:

These come with the central spool and are perfect for absorbing high pressures. Most Z shaped pipe systems require this variant.

Tie Rods/Swivel Tensions:

These variants come with tie rods or swivel tensions according to the amount of pressure. As mentioned earlier, in case for low pressure one can go with tie rods. But in case of high pressure systems it is advisable to use a variant with swivel tensions.

The lateral expansion joints are highly flexible in their designs and thus can be altered to address the various needs for various system components. This flexibility coupled with their lateral movement absorption capacity makes them one of the widely used bellows today.

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