If I understand the question it is: We have a material qualified as an S number on the PQR, but it also has a P number counterpart so can we weld the P number based on the S number qualification? Under Section IX 2007 the answer is no. The test in the P number qualifies for both P and S, but testing the S number does not qualify the P. However, one of the worthies (I really can't remember who) posted recently that S numbers were going away. I assume this is for Section IX:2010. As I don't have copy of IX:2010 available yet, I can't confirm this. Welding P numbers based on a S number qualification may be allowable under IX:2010, but that would need to be confirmed from that revision. Sorry I can't give a more definite answer, but our department just ordered the 2010 and I don't expect it to arrive for a bit. There should be a few people around with the 2010 in hand.