2. Angle Flange
3. Weld End
4. Liner (Baffle)
6. Particulate Barrier/Insulation
7. Liner Seal
Internal liners are used to reduce turbulence across the bellows, and to protect the bellows from erosion. They are necessary when particulate barriers and purges are specified. Liners are normally required when ducts are refractory lined, as they become refractory lined as well. Applicable lateral and angular movements should be specified, in order that adequate clearance is provided in the liner design. Flow direction should be specified on expansion joints with combination ends.
External covers are recommended to protect the bellows from mechanical damage. They may also be utilized for the application of insulation when the ductwork is insulated as well. Covers may be provided in removable and non-removable configurations.
PARTICULATE BARRIER/PURGE CONNECTIONS
In systems that have a media with significant particulate content (i.e. flash or catalyst), a barrier of ceramic fiber can be utilized to prevent corrosion and restricted bellows flexibility resulting from the accumulation of the particulate. Purging systems may also be used to perform this function. Liners will necessarily have to be installed when a particulate barrier or purge connection is specified.
Rectangular expansion joints may come equipped with hinges, tie rods, etc., that can be used to control movements, restrain pressure thrust, or support external loads. This hardware may be installed internally or externally.