Guidelines for inspection and nondestructive testing of paper machine dryers, Technical Information Paper TIP 0402-16 (2026)

This Technical Information Paper (TIP) provides guidelines for inspecting cylindrical, steam-heated pressure vessels made from gray cast iron (GCI) and used as rotating dryers in papermaking. These guidelines also apply to unheated GCI cylinders of the same construction. Large Yankee dryers typically used on tissue machines are not addressed in this TIP.

These guidelines are limited to inspection of the dryer pressure vessels themselves. Inspection of related steam and condensate piping, relief valves, bearings and gears, and doctoring devices is not directly covered. Nevertheless, the inspector should report unusual symptoms and conditions in those components and include that information in the inspection findings as soon as they are detected, in order to prioritize the suspect dryers for detailed inspection at the earliest opportunity in the out-of-operation mode (i.e., during a dryer shutdown).

This document complements TAPPI publication, Guidelines for the Safe Operation of Steam Heated Paper Machine Dryers (1). The inspection and nondestructive testing (NDT) methods recommended in this TIP can apply to dryers made from other materials, including cast ductile iron and cast carbon steel, however, dryers made from GCI require additional consideration due to the unique material properties, specifically the lack of a well-defined elastic limit.

This TIP does not describe how to assess the significance of damage revealed by inspections. In that regard, API 579‑1/ASME FFS‑1 “Fitness-For-Service” (2), a post-construction code accepted by the National Board of Boiler and Pressure Vessel Inspection Code, provides rules for assessing fitness for service of pressure vessels, including a dryer with corrosion and wear damage. Guidelines in this TIP do not supersede local jurisdictional and regulatory requirements.