Dryer Head Capscrews (Bolts)
Dryer head capscrews (bolts) are inspected using a manual ultrasonic soundness
technique where a sample bolt is notched to provide a reference standard and each bolt or a sampling of the bolts are
individually subjected to an ultrasonic examination that will detect significant cracking or discontinuities in the bolt.
The cast heads of the dryer cans are typically designated as drive side or tending side based upon their location. Radii,
bolt rings, manways, lettering and journals are potential areas for cracking. A magnetic particle examination is
performed to detect relevant linear indications that could be detrimental to the integrity of the dryer.
An internal visual examination is performed to detect any mechanical damage or other anomalies that may be present.
Siphons, counterweights, and other attachments are checked for tightness, positioning and wear. Physical
measurements are made of any pits, grooves, water depth, or erosion detected. Photography is often employed to
document any findings. Magnetic Particle examination is sometimes prescribed to investigate internal surfaces as well.