P number quandry: 1 vs 3 ?
P number quandry: 1 vs 3 ?
(OP)
We're planning construction of a non-code pressure vessel for REMOTE testing of reactive chemistry. (OK, explosions). Nevertheless, I refer to the BPV code for guidance in welding and optimizing the strength of this reusable vessel. It consists simply of a 36 in OD pipe x 0.6 wall alloy API 5LX65. Slip on flanges of A694F65 welded at pipe ends and dome closures of A51670N with same mating flanges. Domes have center thru-bosses of A572Gr50.
QUESTION: My initial take on these 4 alloys shows all are P#1. I found no chromium values on vendor sites. Yet, when I look at the mill test certs, API5Lx65 shows chromium at 0.02(%) and A516-70N shows chromium at 0.08(5). So, does this report make the two alloys as P#3? Am I missing a minimum threshold or something??
Gratefully, Montec
QUESTION: My initial take on these 4 alloys shows all are P#1. I found no chromium values on vendor sites. Yet, when I look at the mill test certs, API5Lx65 shows chromium at 0.02(%) and A516-70N shows chromium at 0.08(5). So, does this report make the two alloys as P#3? Am I missing a minimum threshold or something??
Gratefully, Montec





RE: P number quandry: 1 vs 3 ?
RE: P number quandry: 1 vs 3 ?
RE: P number quandry: 1 vs 3 ?
It still requires some knowledge of ferrous alloys and the ultimate application to judge which elements may be significant at, say 0.10%, and whether they were added deliberately. Cr and Ni are usually not significant at that level, Nb and V might be.