Externally Pressurized Type



· Ensure pressure stability
· Absorb large axial movements
· Self-draining convolutions
· Requires main and directional anchors
· No additional liner

Types of Movement

· Axial compression or extension
· Limited lateral and/or angular movements


Externally pressurized expansion joints are suited for piping systems that require large amounts of axial movement. In externally pressurized expansion joints, the bellows elements are arranged so that the media flow is on the external surface of the bellows. Externally pressurizing the bellows eliminates pressure instability as a limitation to the design and permits the absorption of large amounts of axial expansion.

This type of expansion joint does not require maintenance or need lubrication or repacking, therefore making it ideal in areas where accessibility is limited.

Externally pressurized expansion joints come with drain port. The sediment or residue collects at the bottom of the casing for easy venting, thus reducing the corrosion problems.

The outer cover contains the full line pressure of the system, thus in the event of bellows failure, the media could not escape radially outward and harm personnel in the area.