Sulphuric Acid material selection 2

[flexibox]

I would be interested to get confirmation on the following:

I have an application with 99.2%wt% H2SO4 at 30.4C and believe that using 316 Stainless Steel metal parts is suitable. Can anybody confirm this material selection?

thank you in advance

 

[Metalguy]

If there is no flow (tank) and the acid will remain that pure (no water pickup), carbon steel will work fine. Otherwise use 304 instead of 316. The Mo in 316 doesn't help, and Carpenter data indicates 304 is better.

"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein

 

[EdStainless]

http://www.outokumpu.com/applications/corrosion/view_details.asp?name=SU07

304L looks good.

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Plymouth Tube

 

[HowJoh]

Doug Louie's web site "Sulphuric Acid on the Web" has a materials section (

http://www.sulphuric-acid.com/techmanual/materials/materials_metals.htm)

which may be useful to you. Note there the factors that affect corrosion; slight variations in them can have a dramatic effect on the corrosion rate.

 

[flexibox]

Thank you HowJoh, Good information.

 

[blacksmith37]

Refinery alkylation units are generally sulfuric acid. Materials of construction are various carbon steels.Acid conc. is supposed to be maintained above about 95%, ideally 98+. These units operate at roughly 10 to 20 C. Many units with many decades of carbon steel service. Of course there are problems :acid diluted below 95%, localized high velocity, deposits (under which dilution occurs), etc.Some parts of the process were warmer and 30C would not be a problem.