5 replies to this topic

[sumano]

As per section 11.1.3 of API 574:

"In low-pressure and low-temperature applications, the required pipe thicknesses determined by the Barlow formula can be so small that the pipe would have insufficient structural strength. For this reason, an absolute minimum thickness to prevent sag, buckling, and collapse at supports should be determined by the user for each size of pipe."

Table 6 (attached ) of the same code provides some data for Carbon and Low-alloy Steel Pipe at less than 205 degree centigrade condition.

My question is how this strength is measured and in case of temperature higher than 205 degree centigrade what are the values.

Attached Files

•  table 6.pdf   104.53KB   207 downloads

[DYAN ISW]

i have table continues ( NPS 24" to 54 " ). and please i have based on recommended practices for refinery Inspections for pipe diameter 1/4" - 54" .

Thanks before

[kkala]

The query was published in 5 Oct 2012. It has some relation to thread http://www.cheresources.com/invision/topic/15986-minimum-plate-thickness-for-low-pressure-vessels/ concerning vessels.
Then I did not manage to give a reply to the query; thinking of mentioned vessels thread, probably buckling criteria (not measurements) is the base of minimum pipe thickness stated. And for temperatures above 205 oC, rigorous strength analysis should be specifically performed according to real forces exerted on the pipe, without short cut methods. This would be a task for the piping (or mechanical) engineer.
This is a thought for want of something more specific, which would be appreciated.

Edited by kkala, 17 January 2013 - 07:10 AM.

[DYAN ISW]

I need a table 6 from NPS 1/2 "up to 56" for the calculation of Remaining Life Calculation.

[DYAN ISW]

Request Table 6 - Minimun Thickness For Carbon and Low-Alloy Steel Pipe diameter 26" - 54". Please

[kkala]

The most complete table I know is Perry's "Properties of Steel Pipe" (Table 10-18 in the 7th edition), providing all (standardized) thicknesses of commercial pipes from 1/8" to 30" (included) according to North America standards. I thought that sizes above 30" were not commercially standardized. Hopefully somebody expertized in piping could respond to posts 4 and 5.

Edited by kkala, 26 February 2013 - 02:23 AM.