Buried Pipe Design (B31.3 & DOT) - API 1102 vs ASCE
Buried Pipe Design (B31.3 & DOT) - API 1102 vs ASCE
(OP)
As far as I am aware, there are two different codes that can be used for buried pipe design underneath a road crossing: API RP 1102 for Steel Pipelines Crossing Railroads and Highways AND ASCE Guidelines for the Design of Buried Steel Pipe.
I am having trouble coming up with any major difference that would cause me to choose on over the other. It seems that API 1102 might be more conservative in most cases; but since it defines highways as any roadway that is traversed by a propelled vehicular traffic, it would cover all crossings that ASCE covers.
API 1102 does not ever reference the ASCE code, but ASCE references the API code in regards to pipe ovality (less than 3%) and in fatigue.
Do any of the ASME B31 codes call out API 1102 in particular as the code of choice for design? I have not been able to find anything. DOT 195 only says that "The pipe at each railroad or highway crossing must be installed so as to adequately withstand the dynamic forces exerted by anticipated traffic loads." So that's no help.
My main question is, if I am designing a process pipe (to B31.3 & DOT regulations) that is stainless steel going under an HS-20 designed roadway at a plant -- why would I choose one design standard over the other?
For what it's worth, I have already done the design in the example and just ended up following the guidelines for both codes per the specified pipeline. It passed under both design standards, I am merely asking for future reference of why one vs. the other.
Thanks,
-G
I am having trouble coming up with any major difference that would cause me to choose on over the other. It seems that API 1102 might be more conservative in most cases; but since it defines highways as any roadway that is traversed by a propelled vehicular traffic, it would cover all crossings that ASCE covers.
API 1102 does not ever reference the ASCE code, but ASCE references the API code in regards to pipe ovality (less than 3%) and in fatigue.
Do any of the ASME B31 codes call out API 1102 in particular as the code of choice for design? I have not been able to find anything. DOT 195 only says that "The pipe at each railroad or highway crossing must be installed so as to adequately withstand the dynamic forces exerted by anticipated traffic loads." So that's no help.
My main question is, if I am designing a process pipe (to B31.3 & DOT regulations) that is stainless steel going under an HS-20 designed roadway at a plant -- why would I choose one design standard over the other?
For what it's worth, I have already done the design in the example and just ended up following the guidelines for both codes per the specified pipeline. It passed under both design standards, I am merely asking for future reference of why one vs. the other.
Thanks,
-G





RE: Buried Pipe Design (B31.3 & DOT) - API 1102 vs ASCE
http://www.eng-tips.com/viewthread.cfm?qid=358829
http://www.publications.usace.army.mil/USACE-Publi...
So... you must first determine if you simply are designing some kind of underground process pipe on private land, or if you will be covered by the legal provisions of CFR 195. CFR 195 references ASME B31.4, which in turn references API 1102. If the pipeline crosses roads with public right of way or the crossing area can otherwise be accessed by the public, CFR is likely to apply so use API 1102. If that is true, you may be faced with becoming a regulated, or non regulated pipeline company, with all the data reporting and compliance issues that go along with it. My recommendation is, if you are not a pipeline company already, stay on your own land with the pipe works and control access with fences and locked gates (company personal only).
RE: Buried Pipe Design (B31.3 & DOT) - API 1102 vs ASCE
As evidence, look at the hydro testing requirements. Each weld has to be 'felt up' during the hydro; kinda tough to do after backfill. Switch to B31.8 for this crossing, or put in a culvert [using a coated Sch40 pipe 2 sizes larger than the fluid-carrying line] and cross the road that way. Now your process line is not underground, and is inspectable & repairable.
RE: Buried Pipe Design (B31.3 & DOT) - API 1102 vs ASCE