Corrosion of SS304 while SS316 remains intact
Corrosion of SS304 while SS316 remains intact
(OP)
Good day to everybody,
I am not a corrosion engineer but there is a really weird case here. I would appreciate if somebody can give a hint.
We have production manifold equipped with SS 316 strainer mesh welded onto a CS perforated plate. Manifold is feeding 5 compressors in parallel, and each one of them is equipped with a conical strainer made of SS 304 welded onto CS perforated plate.
The manifold handles 2-phase flow consisting of sweet gas at 6 barg pressure, and produced water (pH~5.5 and 20,000 ppm Chloride). Compressor suction lines normally handle gas ONLY but this is the only point where corrosion has been observed.
Can you throw some light on this phenomena?
Many thanks in advance.
I am not a corrosion engineer but there is a really weird case here. I would appreciate if somebody can give a hint.
We have production manifold equipped with SS 316 strainer mesh welded onto a CS perforated plate. Manifold is feeding 5 compressors in parallel, and each one of them is equipped with a conical strainer made of SS 304 welded onto CS perforated plate.
The manifold handles 2-phase flow consisting of sweet gas at 6 barg pressure, and produced water (pH~5.5 and 20,000 ppm Chloride). Compressor suction lines normally handle gas ONLY but this is the only point where corrosion has been observed.
Can you throw some light on this phenomena?
Many thanks in advance.





RE: Corrosion of SS304 while SS316 remains intact
RE: Corrosion of SS304 while SS316 remains intact
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Corrosion of SS304 while SS316 remains intact
With wet gas the conditions probably shift, sometimes wetter and sometimes dryer.
The result is that impurities (salts) can concentrate on the material. The residue on the surface of the 304 is likely saturated (25-30%) brine.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: Corrosion of SS304 while SS316 remains intact
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Corrosion of SS304 while SS316 remains intact
I has slightly better pitting resistance.
If you have seen rapid attack of the 304 though I doubt that 904L is good enough.
A 6%Mo superaustenitic or even a NiCrMo (C type alloy) may be what it takes.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: Corrosion of SS304 while SS316 remains intact
You didn't mention the CS Perforated Plate? I'm assuming since the 304 SS is being corroded, the CS plate should be destroyed by now.
RE: Corrosion of SS304 while SS316 remains intact
In most environments that attack 304, 316 will eventually corrode also.
It will take longer for the corrosion to start in 316.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: Corrosion of SS304 while SS316 remains intact
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Corrosion of SS304 while SS316 remains intact
The SS will suffer localized pitting and crevice corrosion, it will have holes in it first.
= = = = = = = = = = = = = = = = = = = =
Plymouth Tube
RE: Corrosion of SS304 while SS316 remains intact
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
The plural of anecdote is not "data"
RE: Corrosion of SS304 while SS316 remains intact
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Corrosion of SS304 while SS316 remains intact
RE: Corrosion of SS304 while SS316 remains intact