As a follow up to a previous massage I would appreciate info on acceptable rejection rates for the following scenarios:

Both cases are in a petrochemical environment using GTAW and SMAW, with rejection rates calculated as butt’s rejected vs. butt’s tested for pipe welding (butt rate). We weld mostly carbon, low alloys and stainless steels. Please note that we are using radiograph (X-ray) results only for our calculations. (We realize that in using radiograph results only we are not painting the complete picture, but this is the only inspection technique we have reliable data for)

1. What will be the benchmark for rejection rates, using radiographs only, for new fabrication under shop conditions using ASME B31.3 as inspection criteria for radiographs?

2. What will be the benchmark for rejection rates, using radiographs only, for maintenance welding under field conditions using ASME B31.3 as inspection criteria for radiographs? Where mostly old and new material are joined.

Thank you for your inputs.

Joe