By 3.1 Inspector
Date 05-07-2008 12:54
Gentlemen and experts,
How do I use ASME B16.5 table 2?
I am studying for API 570, some of the closed book questions are:
"What is the test pressure for a class 150 API 5L pipe GrB with a A105 flange material at a design temperature of 500F"
18 bar?
30 bar?
19,6 bar?
225 psi?
Heh :)
3.1 Inspector,
Had a quick look at B16.5, it is Pipe Flanges and Fittings so will not help with your pipe.
You would also need to know what class the flange is to give you the working pressure based on Table 2.1.1
However, I always thought test pressure was based on design pressure and not working pressure ?
Sorry I couldn't be of much help,
Regards,
Shane
Your question is not clear.
API 5L is linepipe. The expression Class 150 applies to flanges, not to pipes. A 105 is material for forged flanges and fittings. So, putting all together, I get to the conclusion that you want to test a section of pre-fabricated piping made of API 5L that has one (or more) A 105, class 150 flanges on it. Right?
Now, you're asking for the pressure not in terms of percentage of the design pressure, but in bars or psi.
The bars (or psi) the piping is to be tested to depends, as Shane correctly says, on the design pressure. What's the design pressure of this particular piping?
There's another reason we can't give you an answer: the design pressure depends also on the thickness, which you don't say.
Giovanni S. Crisi
Sao Paulo - Brazil
By 3.1 Inspector
Date 05-08-2008 04:37
I worded the question EXACTLY as I got it presented :(
J
I don't have that cert, but here is how I would attack this problem:
I would determine the maximum allowable pressure for an A105 class 150 flange at 500F first. The hydro pressue will be whatever the amount above that value as specified in the applicable code (ie - MAWP x 1.5).
Alternatively, maybe 5L flatly specifies the test pressure for Gr B pipe.
Good luck.
Charles
Charles,
your approach is good. I would add the following:
Apparently, what Inspector wants to test is a piece of API 5L pipe with one or more class 150 flanges welded to it.
Chances are (great chances, I'd say) that the testing pressure of the flange is different than the testing pressure of the pipe. In this case, the test pressure of the assembly would be the lower of the two. Agree?
Now, if the flange is subjected to 500 F, the pípe will be as well.
Giovanni S. Crisi
