A cylindrical body welded inside the Expansion Joint, one end free to allow the Bellows to move
They prevent the direct contact of flow medium with Bellows
They are used
Whenever required they are installed at the sealed end of each inner sleeve of an Expansion Joint.
A liquid or gas can be injected thru purge connection between the Bellows and internal sleeve to keep the area clear of erosive and corrosive media and / or solids that could pack the convolutions.
Purging may be continuous or intermittent or at start up or shut down as required.
A cylindrical member to cover the Bellows outside, removable type, made of two or more halves
One end fixed and other end free to allow Bellows to move
Facilitate for external insulation of Bellows