Project Description

Perma-Pax Packed Expansion Joints

In this paragraph, I am going to tell you about Perma-Pax Packed Expansion Joints. First thing they are designed for installations where the principal movement is axial. Next standard single and dual designs are available 2″ through 24″ diameter with travels of 4″, 8″ and 12″ compression for single designs, and 8″, 16″ and 24″ compression for dual designs. Furthermore, service conditions are 150 and 300 psig to 500°F. Moreover, welded and flanged end connections are standard, with grooved ends optional.

Perma-Pax Packed Expansion Joints incorporate design features that are not available from other companies. Additionally they include a one piece body which eliminates a circumferential weld. And line bored aluminum bronze metal inner and outer guides. And an optimized sealing system consisting of carbon fiber graphite impregnated braided packing combined with Grafoil® Flexible Graphite injected packing. These features combine to provide a standard product with the lowest seal resistance force available, self lubrication, and precision internal metallic guides.


  • Standard designs sizes 2″ through 24″, 150 & 300 PSIG at 500°F.
  • Axial travel of 4″, 8″ & 12″ for single configurations, 8″, 16″ & 24″ for dual anchor base configurations.
  • Minimum friction force.
  • Carbon fiber graphite impregnated braided packing combined Grafoil® Flexible Graphite injected packing
  • Line bored abrasion free aluminum bronze internal & external guides.
  • Self lubricating maintenance free.
  • They can be repacked under full system pressure.


In this paragraph, I am going to tell you about quality. Firstly Perma-Pax Packed Expansion Joints are a premium quality product with standard features. And the sealing system consists of carbon fiber yarn impregnated with graphite. Particularly these sealing materials remain flexible throughout the service life of the expansion joint. Therefore, have the added benefit of providing lubrication to the traveling pipe.

In addition to, these design features combined with the quality system that includes welding to ASME Code Section IX, and hydrostatic testing and cycling of all Perma-Pax expansion joints, assure the user of a quality extended life product. Design conforms to ASTM F 1007 and Mil-E-17814. We can help design and manufacture expansion joints for custom applications. Which include elevated pressure, and temperature service, special materials, and diameters greater than 24″. A perma-pax expansion joint is a type of metal expansion joint. Click here to read the blog post about pipe expansion joints.


Particularly expansion joints are designed for installations where the principal movement is axial. Furthermore single configurations are 4″, 8″ and 12″ of axial compression (pipe expansion) and 1″, 1.5″ and 2″ extension respectively. Then, if the primary movement is extension (pipe contraction), the expansion joint can be preset at the factory. Finally the piping system must include anchors to react the force produced by pressure thrust and the friction force, supports to react the weight of the pipe and media, and guides to ensure that the pipe alignment is maintained.