Large Diameter Steel Pipe Pressure Ratings
Large Diameter Steel Pipe Pressure Ratings
(OP)
I'm trying to determine the appropriate wall thickness for a 60 inch diameter steel pipe required to withstand 1,000 psi. Don't know if ASME B31 will have the answer but don't have that as a resource at the moment. Can you help? Thanks.





RE: Large Diameter Steel Pipe Pressure Ratings
P=2*S*t*F/D
P-pressure
S-SMYS (specified minimum yield strength of your pipe, e.g. 52,000 psi)
t-Pipe wall thickness
F--Design Factor (between 0 and 1, generally between .5 and .72 for DOT reguated work)
D-Pipe outer diameter
RE: Large Diameter Steel Pipe Pressure Ratings
That must be less than the hoop stress allowable, which will be pipe's minimum specified yield stress / Design Factor.
The B31.4 AND 8 design factor must be found from an area class determination and could be anywhere between 0.4 and 0.8 B31.3 uses one defined allowable stresses. Both design factors and allowable stresses must be derated for temperatures and joint factors, some materials are not allowed. To hoop stress you must add longitudinal and temperature stresses from various load cases and be sure combined stresses are less than combined stress allowables. I think its better that you find a copy of B31.X, where 0 < X < 13
ANSI B31.1 Power Piping Systems
ANSI B31.2 Industrial Gas and Air Piping Systems
ANSI B31.3 Petroleum Refinery Piping
ANSI B31.4 Liquid Petroleum Transportation Piping
ANSI B31.5 Refrigeration Piping Systems
ANSI B31.6 Chemical Process Piping
ANSI B31.7 Nuclear Power Piping
ANSI B31.8 Gas Transmission and Distribution Piping
ASME B31.9 Building Services Piping
ASME B31.10 Cryogenic Piping (never published)
ASME B31.11 Liquid and Slurry Piping Transportation Systems
ASME B31.12 Code for hydrogen piping and pipelines.
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RE: Large Diameter Steel Pipe Pressure Ratings
2) Is the SMYS example you give somewhat of a standard or reasonable expectation for a steel pipe application? If I use 52,000; and the 1,000 psi spec my customer is seeking, the forumula yields 0.96 inches thickness (with F at 0.6) which is a number that seems to make sense to me (if I have any sense at all). I'm guessing that 1" thick wall on a 60" diameter pipe might make sense. Does this make sense to you? Thanks again.
RE: Large Diameter Steel Pipe Pressure Ratings
52,000 psi is a middle of the road standard pipe commercially availble steel pipe strenght. You can get pipe in the following grades, Grade B (35,000 psi), X42, X52, X60, X65, X70, and a limited number of mills make X80. (where X52=52,000 psi SMYS).
The higher the strength, the thinner the wall can be so, it boils down to a cost issue...if it's a lot of pipe you'll probably end up going with X70 and a thinner wall.
Also, with 60" pipe, the only "off the shelf" sizes wall thickness are .375" and 0.500" w.t., so you're looking at a custom order...and 1" sounds about right if you're using a appropriate design factor for your application.
RE: Large Diameter Steel Pipe Pressure Ratings
"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.liv
RE: Large Diameter Steel Pipe Pressure Ratings
RE: Large Diameter Steel Pipe Pressure Ratings
"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
http://www.youtube.com/watch?v=hpiIWMWWVco
"Being GREEN isn't easy." Kermit
http://virtualpipeline.spaces.liv