CONTROL RODS
- For individual Bellows in an Universal Expansion Joint.
- To limit the movement per Bellows.
- Not designed to withstand the Bellows Pressure Thrust Load in the event of Anchor failure.
LIMIT RODS
- Installed in Untied Expansion Joints to restrict the Bellows movement range during normal operation.
- In the event of a main anchor failure, they are designed to prevent the Bellows over-stretching or over-compression while restraining the full pressure thrust load.
PANTOGRAPH LINKAGES
- A scissors-like device.
- Primary function is to positively distribute the movement equally between the two Bellows of the Universal Expansion Joint throughout its full range of movement.
- Pantograph linkages are not designed to restrain pressure thrust.
INTERNAL SLEEVE
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
PURGE CONNECTION
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.
EXTERNAL SHROUD
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
Prevent the damage of Bellows
- From falling objects.
- During handling and transport.
- From weld arc strike / spatter during welding at adjoining areas.
SHIPPING BRACKETS / SHIPPING RODS
- Brackets or Rods fixed at both sides of a Bellows.
- Generally painted in yellow colour.
- Helps to maintain the Overall Length of the Expansion Joint during transportation, handling and installation.
- They should be removed after completion of installation of Expansion Joint, Pipe Supports, & Guides and prior to Pressure testing of the line.