Clamshell Expansion Joint

Arcflex clamshell metal expansion joints are designed to absorb movements in all three directions i.e. axial, lateral and angular – they come in separate halves which are then welded together.  Clamshell bellows are often used when an existing bellow needs replacing urgently which means they are the perfect solution when an unexpected replacement is required.

Types of clamshell expansion joints:

  • Clamshell expansion joint same- size:

To install this kind of clamshell bellows, the whole piping system will need to be shut down.  The existing bellow is removed and replaced by new clamshell bellow of a similar size.  The replacement clamshell bellows’ inner diameter is same as the existing bellow’s inner diameter.

clamshell same pipe size

  • Clamshell expansion joint over-size:

To install this kind of clamshell bellows, the whole piping system doesn’t need to be shut down.  The over-size clamshell bellow is installed on top of the existing bellow.  These kind of bellows are welded on split rings, with the larger bellows inner diameter greater than the existing bellows outer diameter.  This will result in an increase in the bellows deflection and effective area.

clamshell over pipe size