Liners are used to prevent flow induced vibration or erosion caused by abrasive materials. When lateral movement is required in the expansion joint, the flow liner diameter must be reduced to provide clearance.

Drop-in liners are used when conditions require frequent replacement. This type of liner can also be furnished in a telescoping configuration. Gaskets are required on both sides of liner face to effect a seal. Sometimes called a top-hat liner.

Telescoping liners are used on short expansion joints with large axial movements. When fit close together, they can also be used in systems where the flow can be in either direction.

Removable covers are required on flanged expansion joints in order to tighten the bolts during installation. They also can be removed for inspection purposes. In the event of a leak or failure, the shroud can help to deflect the steam or other media.

All shrouds help to protect the bellows from damage. This type of cover is used when removal of the shroud for installation is not necessary. DME welds the cover in place after the expansion joint has been inspected and pressure tested.

Tie rods are used to restrain the thrust forces created by the internal pressure of the expansion joint. Normally the system anchors are used to withstand the thrust forces.

Control rods are devises that limit the individual travel of each bellows in a universal or dual expansion joint. These rods can also be designed to support external loads. Control rods are not normally designed to absorb the pressure thrust loads.

These control devises are used to limit movement to the design capability. In the event of an anchor failure, the rods will absorb the full pressure thrust loading of the expansion joint.

Hinges are control devises that limit the bellows to angular movement in one plane only. Standard hinges do not require anchors. Slotted hinges will also permit axial travel but must have anchors in the system.

A female NPT port can be added to any expansion joint provided there is a pipe or tube section. Ports are used as a drain, to inject steam, for instrumentation, or other applications.

Anchor bases are designed to absorb the spring forces of the bellows. Single expansion joints with anchor bases are placed at one end of the piping system, not in the center.

Dual expansion joints allow for large amounts of axial movement. They must be placed in the center of the piping run and secured by using an anchor base.