Richard, if your test is tomorrow (Monday) you might not get any advise from the pipeliners in time to help you.
I'm not an experienced pipe line welder so I am not qualified to help you.
Your best bet is to use the search feature and type in branch test. Look especially at the post made by dbigkahunna. He has explained it in detail.
Good luck with it and let us know how it goes.
dont close down a wine shed tonight and pack a lunch. Have your tips cleaned, a roll of adding machine tape, tape measure and a graves blue book. Depending on your torch skills, have plenty of grinding disk. I am taking for granted you know how to lay out and cut a branch. If you dont, there is not anything you can learn tonight that is gonna help you.
BABRt's