0kujobew

MarkMark220 wrote:

Pipe schedules indicate approximate values of the expression 1000 x P/S where P is the service pressure and S is the allowable stress, ...... the standard manufacturer's allowance on wall thickness which is 12.5%....

Can you explain it to me with an example: What schedule I need for a pressure of 50 bar or 750 psi?

vs2r3

Robertobe, the following example from "CASTI guidebook to ASME B31.3 modified to 750 psig (their example used 600 psig)

Let's say you were using A-53B, Sh for this pipe is 18,900 at 500F.

Schedule = 1000 * P / Sh = 1000*750/18,900 or 39.68.??You would use the next size commercial pipe which is schedule 40.??If you included the standard 12.5% allowable variation in wall thickness, you'd have to choice a higher schedule than 60.

Note, this method is no longer used to actually size pipe, you should use the equations in the appropriate code to determine your minimum thickness, taking into account allowable manufacturing variations and corrosion allowances.

6gjhje

manufactures's allowance on thickness of pipe is on positive side or negative?

drill8dr

Mfr tolerance on thickness is plus or minus 12.5%

619853t1

dear sir, if you want to check existens schedules for comercial steel and associated characterístics you can find this information on CRANE TECHNICAL PAPER No. 410?????" FLOW OF FLUIDS THROUGH VALVES, FITTINGS, AND PIPE" pp b-16 thru b-19 for diameters from 1/8" to 36".

stonegeo

This is my first time on this site and I just wanted to post a question in this forum so, I found this link and I hope someone can help.

I was wondering if anyone knew who sells schedule 40 pipe to companies in the natural gas industry. As small as 1".?
Either a muanufacturer or supplier in Canada or the U.S.?

if you can't post a response here, please contact me at
[url=mailto:bravestar143@hotmail.com]bravestar143@hotmail.com[/url]
.

I would really appreciate any feedback!

gas323ge

vmartins

You can try the two links below.


http://www.red-man.com/



http://catalog.natoil.com/cgi-bin/online/OC_product_catalog.jsp?BV_SessionID=@@@@1095670717.1042654589@@@@&BV_EngineID=cccladchdehhiekcfngcfkmdgmgdffh.0&category=General%2fTubular+Goods


In the future you may want to post your questions on a new thread not just add to an existing one.??Your question will be reviewed by more people giving you more answers.

Hope this helps!
David??

geo39saf

TD2K, in your reply to Robertobe, where can I find the allowable stress (i.e. 18,900 in your example) for different pipe???Does this number apply to all A53 pipe???If so, what is the number for 316SS pipe?

dbjob6a2

Wow, this is a blast from the past.

First, this is an obsolete method to size what pipe you need.??That said:

Allowable stresses can be found in B31.3 and likely a bunch of other reference materials.??

The values will vary depending on the grade of A53 you are using.??A53 GrF for example at 500F is limited to 400F at a value of 13,800.??A53 GrA is 16,000 at 500F.

316SS has a value of 17,900 at 500F.??316L has a value of 14,400 at 500F.