schedule & maximum pressure

By NK Date 02-28-2007 14:18

Hi all,

I just joined today, and hope the question I'm about to ask is an allowed and relevant one here:
I've been working with a consultancy agency for about 6 months now, and have one question:

When looking at the different pipe scedules, where can I find the allowed working pressures for these pipe sizes and thicknesses?
This question goes for both ASTM and API.

Should anyone have an answer to this, it will be greatly appreciated!

Greetings,
Nard

By js55

Date 02-28-2007 14:28

Allowable stresses are also related to temperature, and data can be found in ASME Section IID.

By NK Date 02-28-2007 14:37

Thanks!

Is there anywhere on the internet where I can find this?

By RANDER

Date 02-28-2007 14:53

Infocentral@asme.org

By js55

Date 02-28-2007 15:57

I'm not sure this data would be avaiable on the net. Its possible. I don't know where it would be though. Folks like to charge for this kinda stuff.

By Soheyl Date 02-28-2007 19:09 Edited 02-28-2007 21:22

hi,
if you refere to ASME B31.3 under section 304.1.2 there is a formula which you can check internal pipe pressure against pipe wall thk.

By dbigkahunna (****)

Date 03-01-2007 11:47 Edited 03-01-2007 11:59

The schedule (thickness) of the pipe is one consideration when calculating the pressure rating. Grade and pipe size are others. B31.3 has tables which show the pressure and temperature rating.Weld efficiency is determined by type of seam weld. Seamless is 1.0 to lap wled which I believe is 0.50 or 0.35 been a while
The formula is 2SEt/D 2 x Stress (from B31.3 tables) X weld efficiency (from B31.3 Table) X thickness (schedule) divided by diameter
ASME B31.3 Equation 3b

By Sourdough (****)

Date 03-02-2007 02:05

I deal with sch80 and 40 on a regular basis. As a general rule 80 can handle 2500 to 3000 psi, and 40 1500psi max. I have been on jobs that were needing to handle 20,000 psi. Needless to say, I do not take any of these jobs lightly. Code all the way, period. I do not know the code for xx wall stuff, but i always make good penetration with 5p+, a super hot, hot pass, a filler and stringer passes with low hydrogen.