Externally Pressurized Expansion Joint

In the following, I will talk about externally pressurized expansion joints. Firstly they are designed for installations where the principal movement is axial. Secondly, standard single and dual designs are available 2” through 24” NPS with 4” through 16” axial compression. The following service conditions are 150 and 300 PSIG to 500°F. Then welded and flanged end connections are standard, with grooved ends optional.

Moreover, Standard in-line pressure balanced configurations are available 2” through 24” NPS with 4”, 6” & 8” axial travel rated for 150 & 300 PSIG to 500°F. Finally, pipe telescopes into the expansion joint protecting the bellows and providing a smooth entire bore interior. Additionally, contact us for a quote or more information.


• Standard Designs Sizes 2″ through 24″, 150 & 300 PSIG at 500°F
• Axial Travel of 4″, 6″ & 8″ for Single Configurations 8″, 12″ & 16″ for Dual Anchor Base Configurations.

  • Maximum Flexibility and Extended Life
  • Low Spring Forces and Pressure Thrust
  • Standard In-Line Pressure Balanced Configurations

Since the media is on the formed metal bellows, it is self-draining, and metal bellows instability or squirm consideration. Rigid guides on the interior and cover ensure alignment of the pipe bellows. Piping seals can also be used to help with the pipe. The proven design of externally pressurized expansion joints excels because of close attention to detail design and high-quality artistry. In addition, these designs offer an affordable product with a proven service record without expensive high nickel alloys.

Externally Pressurized Joints

Externally pressurized expansion joints are suitable for installation where the main movement is axial. Standard single configurations are used for 4″, 6″ and 8″ axial compression (pipe expansion) and 1″, 2″ and 2″ extensions respectively. We design dual configurations for 8″, 12″, and 16″ axial compression and 2, 4, and 4″ expansion. If the main movement is expansion (pipe contraction), we can set the metal expansion joint at the factory. The piping system should include anchor bolts and permanent elastic corrugated pipes that respond to compressive forces, brackets to support the weight of the pipes and media, and alignment guide devices to ensure the alignment of the pipes.