Summary

Clamshell bellows is an effective solution when a quick and urgent replacement of the bellows is needed. Clamshell bellows are often used when an existing bellows needs replacing. Clamshell bellows is a two-piece bellows which is welded on site. Clamshell expansion joints can be designed as either temporary or permanent solution and as an over-sized or same-sized clamshell metal expansion joint bellows.

Types of clamshell expansion joints

· Clamshell expansion joint over-size
: The whole piping system doesn’t need to be shut down. The over-size clamshell bellows is installed on top of the existing bellows. These kinds 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.

· Same- size
: The whole piping system will need to be shut down. The existing bellows is removed and replaced by new clamshell bellows of a similar size. But it is recommended to use new expansion joint reflected site operating and condition.