wall thickness of compressor stations piping
wall thickness of compressor stations piping
(OP)
hi all
until two days ago I was believing that wall thickness calculations for piping of compressor, metering and pressure reduction stations of gas transmission pipelines follow ASME B31.3 code. but when I started to skim the code; I found it states that piping of compressor stations and other facilities on the pipeline shall follow B31.8 as the pipeline itself.
so please tell me, should I calculate wall thickness of compressor, metering and pressure reduction stations with equations of B31.3 or B31.8
thank you in advance
until two days ago I was believing that wall thickness calculations for piping of compressor, metering and pressure reduction stations of gas transmission pipelines follow ASME B31.3 code. but when I started to skim the code; I found it states that piping of compressor stations and other facilities on the pipeline shall follow B31.8 as the pipeline itself.
so please tell me, should I calculate wall thickness of compressor, metering and pressure reduction stations with equations of B31.3 or B31.8
thank you in advance





RE: wall thickness of compressor stations piping
RE: wall thickness of compressor stations piping
I believe, but can be corrected, that in the US, the mandated code for gas compressor stations is B31.8?
However in many other locations, companies decide to use B 31.3 for all "piping" design and leave the pipeline codes to the offsite stuff. Pipeline codes should, as a minimum, continue to the pig trap and often the first valve off the pipeline.
If you've got lots of long piping runs in large diameter pipe, it can make sense to move that code break further down or even design the whole thing to a pipeline code as they all cover compressor stations.
The downside is that to get advantage of the pipeline codes, you need to use higher grade pipe. That's Ok for the pipe, as B31.3 doesn't give you much, if any, reduction in wall thickness compared to the pipeline codes, but it means you need to use high strength flange and fittings (e.g. elbows, reducers etc) material compared to a "standard" B 31.3 design. As compressor stations tend to have lots and lots of flanges, fittings and valves, the cost element of the pipe gets to be only a small fraction of the materials cost compared to a pipeline. you can also suffer some delay ( perhaps not at the moment(!)) in getting items of a higher strength compared to say A105.
So in summary, yes you can use B31.8 in those locations ( usually has a design factor of 0.6), but this might cause you more problems and increased cost / schedule when you need to buy high strength flanges and fittings. Unless you're in the US you can decide yourself.
Remember - More details = better answers
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RE: wall thickness of compressor stations piping
0.6 is for fabricated assemblies, such as at tie-ins, or block valve assemblies in rural areas, where the area classification would not otherwise require 0.5 or 0.4 .
RE: wall thickness of compressor stations piping
Has it always been 0.5? (other than location class 4)
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: wall thickness of compressor stations piping
In the USA I don't know of any gas transmission companies that use B31.3 for anything other than process units, such as gas treating, dehydration and liquid extraction units. Compression cooler piping, pig launchers/receivers and pipe type slug catchers and drips are CFR Title 49 Part 192 (essentially B31.8) and vessels (coalescing filters, slug catchers, etc.) are always designed to BVP VIII.
When using a DF of 0.5 the difference in wall thicknesses bewteen codes re very small. PHMSA does not object if B31.3 was used (in error) for compressor station design as long as the final design meets CFR Title 49 Part 192.
Of course you must remember that there are many design requirements for pipelines and compressor stations that B31.3 does not address at all, so when designing a pipeline system B31.3 can not really be used for anything more than determining the wall thickness of the pipe anyway.
RE: wall thickness of compressor stations piping
http://www.eng-tips.com/viewthread.cfm?qid=376163
RE: wall thickness of compressor stations piping
RE: wall thickness of compressor stations piping