SS vs. CS in sour gas service
SS vs. CS in sour gas service
(OP)
I have been looking at the NACE MR0175 / ISO 15156-1 standard and trying to determine the discharge material requirement for a sour gas compressor skid at 5000psig, with up to 10 mol% H2S present. The standard is very detailed in it's description of allowable carbon steel and stainless steel material compositions and requirements, but it does not state when each should be used. I know the norm is SS for acid gas systems, but I don't know what makes it "acid" or why SS is typically used over CS. Does anyone have any guidelines? Am I looking at the wrong standard?





RE: SS vs. CS in sour gas service
RE: SS vs. CS in sour gas service
RE: SS vs. CS in sour gas service
RE: SS vs. CS in sour gas service
Steve Jones
Materials & Corrosion Engineer
http://www.pdo.co.om/pdo/
RE: SS vs. CS in sour gas service
To answer your question about the justification for using carbon steel all round, those I know who have done it have had mixed results, if the piping is well designed and has no pockets or stagnant areas and their is a proper corrosion inhibition regime in place, carbon steel can be a good inexpensive work horse, however trying not to sound to synical carbon steel is the obvious choice when you are responsible for the design and build costs but not for the operations costs.
RE: SS vs. CS in sour gas service
RE: SS vs. CS in sour gas service
Just for your information, the API 941 document (Nelson Curves) is for high temperature hydrogen service. They don't apply to H2S (only) materials considerations or design.
~NiM