Guideline for Obtaining High Quality Radiographic Testing (RT) of Butt Welds in Boiler Tubes, Technical Information Paper TIP 0402-33 (2006)

This document is meant to provide technical guidance to mills and qualified providers of radiography testing (RT) services in obtaining high quality RT images when inspecting tube welds in recovery and power boilers. RT of tube welds is accepted by the Black Liquor Recovery Boiler Advisory Committee (BLRBAC).

This document applies to butt welds in tubes up to 4-in. OD with wall thickness less than 0.5 in. This document also can apply for small diameter piping. Tubes can be carbon steel, stainless steel or any combination thereof, including composite (layered) tubes. RT is suitable for new construction and repair welds in the shop or in the boiler.

The guidelines in this document apply equally to RT of tube butt welds by the “elliptical” and “contact” techniques, illustrated herein. A subordinate goal of the document is to describe advantages the contact technique offers over the elliptical technique in appropriate circumstances.

Qualification requirements for people who obtain and interpret RT images are described. Image quality requirements are described but acceptance criteria for weld quality are not given and must be defined by the mill.