Expansion Bellow & Joint

Unrestrained Assemblies

Single Expansion Joint Assemblies are the simplest type of expansion joint consisting of a single bellows element welded to end fittings, either flange or pipe ends.
Universal Expansion Joint Assemblies consist of two bellows connected by a center spool piece with flange or pipe ends. The universal arrangement allows greater axial, lateral and angular movements than a Single Bellows Assembly.
In Externally Pressurized Expansion Joints, line pressure acts externally on the bellows by means of a pressure chamber. This allows a greater number of convolutions to be used for large axial movements, without fear of bellows instability. Externally Pressurized Expansion Joints have the added benefit of self-draining convolutions if standing media is a concern. Anchors and guides are an essential part of a good installation.

Restrained Assemblies

Tied Single Bellows Assemblies add tied rods to a Single Bellows Assembly to increase design flexibility in a piping system. The tie rods are attached to the pipe or flange with lugs that carry the pressure thrust of the system, eliminating the need for main anchors.
Tied Universal Assemblies are similar in construction to a Universal Assembly except that tie rods absorb pressure thrust and limit movements to lateral offset and angulation only.
Hinged Bellows Assemblies limit movement to angulation in one plane. Hinged Assemblies are normally used in sets of two or three to absorb large amounts of expansion in high pressure piping systems.