Guidelines for Evaluating the Quality of Boiler Tube Butt Welds with Ultrasonic Testing, Technical Information Paper TIP 0402-31 (2006)
This document is intended to provide technical guidance to mills and providers of ultrasonic testing (UT) of welds in tubes in recovery and power boilers. UT of welds is done to find flaws that could cause a weld-related leak. Weld quality criteria must be defined by the mill.
A supplementary goal of the document is to encourage use of UT in appropriate circumstances.
This document applies to welds in tubes less than 4-in. OD and wall thickness less than 0.5 in. This TIP also can be used for UT of welds in small diameter piping. Tubes can be carbon steel, stainless steel or any combination thereof, including composite (layered) tubes.
This document describes procedures and requirements to qualify equipment and technicians for this type of UT.
When using this procedure, the mill should:
1. Define the weld quality acceptance criteria.
2. Provide physical standards for technician skill testing and equipment calibration. (Arrangements are usually made for the NDT contractor to provide a calibration standard.)
3. Verify the UT technician’s skill and competency prior to field testing of welds.