I am looking for the maximum pressure of a 3" 300# a-105 slip on flange. I have looked in B16.5 but couldn't find anything for it. I have a customer that wants to Hydro a 3' spool piece at 1150 psi, which is way beyond what it should be if you go 1.5 times the mawp. I really want to make sure I'm not going to get anyone hurt is my main reasoning behind finding this. They told me that 1150 is the max test pressure for that flange rating, but couldn't tell me where to find that. Any help would be appreciated
I have a print out of ASME B16.5-2003, Annex F, Table F2-1.1 Pressure - Temperature Ratings for Group 1.1 Materials (which includes A-105 material): Says a class 300 flange at -20 to 100 degrees F has a working pressure of 740 PSI, which would be 1110 PSI test pressure if multiplied by 1.5.
Why do you think 1150 is way beyond what it should be?
Should'nt these be fabricated off engineered drawings? So the spec will give the test pressure. B31.3 is 1.5 Xdesign and B31.4 is 1.25 X design unless air is used. The customer can alter the test pressure but usually a PE will sign off on it. Has a PE signed off on it?
What schedule is the pipe? 1150PSI hydro isn't going to hurt anyone if you get all the air out. A 3'' 300# Flange will hold over 1150 easy with a flexatalic gasket.
I found it. There were no drawing for this piping. We went to the field where there was a leak and pulled measurements and the customer gave us the information on grade and schedule that they wanted. It was schedule 80 piping. I was looking in B16.5 at 300# 500 deg which was maximum pressure of 600. It didn't click right then that our test was going to be at ambient temperature which made the max pressure 740. Thanks to everyone that responded for all your help.
What schedule is the pipe? 1150PSI hydro isn't going to hurt anyone if you get all the air out. A 3'' 300# Flange will hold over 1150 easy with a flexatalic gasket.
Forum
