Paper machine reel-spool journals: guidelines for crack testing and repair or replacement

This document was created by a TAPPI Task Group to provide information and guidelines for nondestructive testing (NDT) of reel-spool journals used in paper mills. The document describes reel-spool design concepts, failures, inspection, and considerations for repair/replacement.

Reel-spool journal failures are a concern in paper mills. Reel-spools experience high rotational speeds, brake torque reaction stresses and are subject to impact loads from rough treatment on stands, hooks and rails. Failures are infrequent but consequences can include worker injury and severe damage to surrounding equipment. Mills should employ preventive maintenance practices to keep their reel-spools in safe operating condition. The information in this document helps a mill inspect reel-spools for fatigue cracking, the main damage mechanism.

Information provided in this document on journal materials, failure locations and mechanisms, recommended inspection frequency, nondestructive testing (NDT) methods and techniques, etc., generally applies to reel-spool journals of all sizes. The general concepts also are applicable to other journals and shafts.