Good points to consider.

As mentioned by Henry, all the essential variables of welder performance qualification must be considered. Those variables vary slightly from one welding standard or code to another. There is no one test that qualifies the welder for everything. You must consider the process, the filler metal (F numbers com into play), progression (vertical uphill versus downhill progression), was the test taken with or without backing, was only one process used for the entire test or were two (or more processes) used, i.e., GTAW for the root and SMAW for the fill and cover, and the list of variables goes on and on.

In general, a test on pipe does qualify the welder for plate, but within the limits of certain essential variables. So, with that context in mind, Henry and the others ae spot on.

Best regards - Al