Examination of Procedure and Operator

One of the most important functions of an Authorized Inspector is examining welding procedures and operators for their compliance with the intent of Code requirements. The Code does not dictate methods to the manufacturer, but it does require proof that the welding is sound (Code Par. QW-201) and that operators are qualified in accordance with the ASME Code Section IX, Welding and Brazing Qualifications (see Code Par. QW-301). To avoid confusion, it should be noted that all Code references in this chapter, unlike the rest of this book, refer to ASME Code Section IX, Welding and Brazing Qualifications.

An Inspector must be familiar with the physical properties of materials and electrodes and should have experience in the evaluation of the written procedures and test plates required by Section IX. An Inspector also must know how to determine the cause of test plate failures. The manufacturer should actually be more interested than the Inspector in finding the cause, for it is far less expensive to prevent failures than to make expensive repairs. This is especially true if the procedure is to be used on a production line where individual items may miss inspection. In a plant where liquified propane gas tanks were being constructed of a high-tensile-strength material, for example, the manufacturer had difficulty in performing satisfactory bend tests on an offset joint for the head and girth seam. After various changes in welding procedures, a test finally satisfied Code requirements. Because of the history the...