It depends. Dryer fabric tension holds the sheet in tight contact with dryer surfaces to increase the drying rate and uniformity of heat transfer.
Proper flexible metal hose installations prevent stress on rotary joints and unions as well as connected piping due to thermal expansion, vibration, and misalignment.
A rotary joint or “steam joint” is a mechanical seal that connects steam piping to rotating drying cylinders.
An “insulating sleeve” is a flanged tube that extends through the bore of a paper dryer journal.