This Technical Information Paper (TIP) provides guidelines for inspecting modern (c. 1950 or later)
cylindrical cast iron pressure vessels used as rotating, steam-heated dryers in paper machines. These guidelines may
also be applied to unheated cylinders of similar construction like vacuum dryers. However, large diameter Yankee
dryers used on tissue machines, are not covered (1,2).
This guideline is limited in scope to inspection of the dryers proper. No guidance is provided on the
inspection of over-pressure protection devices, external steam and condensate piping systems, bearings and drive
components, or doctoring devices associated with the dryers. Nevertheless, inspectors should not ignore evidence or
conditions with these components that could pose a safety threat or compromise the runnability and reliability of the
dryers and dryer sections. This TIP does not discuss the interpretation of inspection data. See National Board
Inspection Code and ASME Codes for guidance on engineering and design, repair, safety, operation and storage of
dryers (3-5).
These guidelines are not intended to supersede local jurisdictional and regulatory requirements.
