Final answer:
The amount of overlap allowed on a procedure qualification test coupon is governed by the code or standard relevant to the welding process, such as AWS or ASME codes.
Step-by-step explanation:
Regarding procedure qualification tests in welding, the amount of overlap allowed on a test coupon is typically dictated by the specific code or standard being followed, such as the American Welding Society (AWS) D1.1, ASME Boiler and Pressure Vessel Code, or other applicable welding procedure specifications (WPS). It is essential to consult these documents for the exact requirements as they can vary.
Generally, there should be no intentional overlap of welds unless the procedure being qualified specifically allows it, and any overlap that does occur should be addressed according to the criteria laid out in the relevant standard.
For example, AWS D1.1 sometimes addresses overlap under the term 'unacceptable discontinuities' for certain welding processes. To ensure the quality and integrity of the weld, the procedure qualification should reflect the conditions that will be applied in actual production, therefore understanding and following the limitations on overlap is crucial.