The Role of Metal Expansion Joints

Metal Expansion Joints

Expansion joints, also known as bellows or compensators, are flexible connectors that are used in process and HVAC piping systems to absorb movements, such as thermal expansion and contraction, vibration, and misalignment. They are designed to prevent damage to the piping system, equipment, and surrounding structures by allowing for the movement and stress that occurs within the system.

There are several types of expansion joints, including metallic, non-metallic, and fabric. Metallic expansion joints are made of metal bellows and are typically used in high-pressure and high-temperature applications, as well as in applications that require a high degree of corrosion resistance. These expansion joints are typically made of stainless steel, but they can also be made of other metals such as Inconel, Monel, and Hastelloy.

The main function of metallic expansion joints is to provide flexibility in the piping system. They do this by allowing for movement in three main ways:
  • Lateral movement: Metallic expansion joints can accommodate lateral movement, which is movement in a side-to-side direction. This is important in systems that are subjected to thermal expansion and contraction, as the pipes will expand and contract due to temperature changes.
  • Angular movement: Metallic expansion joints can also accommodate angular movement, which is movement in a rotational direction. This is important in systems that are subjected to vibration, as the pipes will vibrate due to the flow of fluid or gas.
  • Axial movement: Metallic expansion joints can also accommodate axial movement, which is movement in a back-and-forth direction. This is important in systems that are subjected to misalignment, as the pipes may not be perfectly aligned.
  • In addition to providing flexibility, metallic expansion joints also help to reduce noise and vibration, and they can protect against the effects of corrosion, erosion, and abrasion. They are often used in a variety of industries, including power generation, petrochemical, pharmaceutical, and food and beverage.
If you'd like to discuss applying metal expansion joints in your application, contact:

Piping Specialties, Inc.
800-223-1468