Sulfuric Acid Material 3

[Valving]

For %80 sulfuric acid application, temperature is around
at max 43 deg. C , which material do you recommend?
I am stuck between Alloy 20 and Hastelloy C series.
Pressure : 1 bar , no impurities.

 

[metengr]

Is there flow or just for storage?

 

[metengr]

Read up

https://www.nickelinstitute.org/~/m...sinsulphuricacidandrelatedcompounds_1318_.pdf

 

[EdStainless]

80% acid is very difficult to handle, alloys like B-2 and B-3 may be the only real options.
You need to know all of the impurities before you select a material, oxidizing species are an issue (Cu, Fe, NO, Cl..)

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P.E. Metallurgy, Plymouth Tube

 

[arunmrao]

I am inclined towards Hastelloy C. However, while handling such corrosive media, you should take professional help with experience . Any failure can be a disaster.


"Even,if you are a minority of one, truth is the truth."

Mahatma Gandhi.

 

[EdStainless]

See if you can find a copy of MTI MS-1 on Concentrated Sulfuric Acid. This a very complete reference on the subject and it was updated a few years ago.

http://www.haynesintl.com/alloys/al...-C-2000-Alloy/comparative-0-1-mm-y-line-plots

http://www.haynesintl.com/alloys/al...ASTELLOY-B-3-alloy/Isocorrosion-diagrams.aspx

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P.E. Metallurgy, Plymouth Tube

 

[moltenmetal]

With dilute acid at conditions which are not very hot, stay the hell away from metals and choose plastic materials, as linings if you're worried about mechanical damage or pressures are high. Corrosion immunity is far better than mere corrosion resistance!

 

[EdStainless]

MM, yes us metal guys tend to think that way don't we?
I wouldn't want to use rubber at this temp but there are plenty of resin systems that would work well.
For this they would use a special glass, structural resin, and (maybe) apply a liner of a different resin.
Google "FRP sulfuric acid"

composites-cis.com/materials/en/15.pd

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P.E. Metallurgy, Plymouth Tube

 

[moltenmetal]

The point here is that an alloy which works at 80% might not work at 70% and might fail rapidly at 60 or 50%- and the plastics will just yawn and laugh off that difference!

 

[pradipgoswami]

Hasteloys are excellent alloys but may be rank expensive.Compered to that Alloy-20(20Cb-3)are more easily available and may be less expensive alloys.Another proprietary alloy, Zecor-Z is also very popular in the sulfuric acid industry, though being proprietary customers could also be at the receiving ends.

It may be worthwhile to know what're the components involved.

Here're some links which might be useful.

Thanks.

http://www2.dupont.com/Clean_Technologies/es_MX/assets/downloads/Equipment_FAQs.pdf

ZeCor -Z alloy:

https://www.atimetals.com/news/corrosion-conference/Documents/CSC09

pdfs/PAPER_5D_GRUBB.pdf

http://www.parrinst.com/wp-content/...arr_Carpenter-20-Stainless-Corrosion-Info.pdf

http://www.corrosionmaterials.com/documents/dataSheet/alloy20DataSheet.pdf

Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
All provided answer are personal opinions or personal judgements only. It's not connected with any employers by any means.

 

[EdStainless]

Zecor and SX (both proprietary) are versions of A610/A611 high silicon austenitic stainless steels. I wouldn't use any of these at 80%, that is way too low for them.

The problem with almost all of these alloys that have been batted about is that their useful concentration range is limited. They will either go to hell at 70%, or at 90%. The exception is B-3, but the cost is steep.

I guess that the question that comes to mind is why do you have 80% acid (sounds odd), and can it ever be more concentrated, or less concentrated?
Look at FRP.

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P.E. Metallurgy, Plymouth Tube

 

[Valving]

Thanks to all input. This is regarding valve material selection.
I searched many literature and websites and have a great database.
Mostly it looks like Alloy20 would be fine. Pls. check the best doc I could find
from carpenter.
However I do agree the concern for higher and lower figures of
% and temp.
I have asked to a few foundries and valve producers
having experience in corrosion field.

If we go to plastic materials, do you recommend FRP?
PVC or others?
Thanks for time and discussion.

 

[EdStainless]

I suggest looking for other iso-corrosion diagrams. That one look a bit too optimistic for my taste.
You need to consider who welds and casting will perform, not just mill annealed and pickled plate.

The FRPs are mad with various epoxy resins. I believe that Ashland chemical has some very good references.

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P.E. Metallurgy, Plymouth Tube

 

[moltenmetal]

Small sizes: solid thermopolymer valves. Larger sizes: butterfly valves with non-metallic internal construction and Hastelloy C stems, or all-lined plug valves from Durco, Xomox etc. I have no experience with FRP valves.

 

[EdStainless]

Often pumps and valves of larger sizes are made from high Si cast iron, but I don't know if it would work in this lower concentration acid.

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

The reference to ATI's Dr. John Grubb's paper by pradipgoswami provides excellent information on High Si alloy behavior in sulfuric acid. The Zecor-Z looks as though it would work.

https://www.atimetals.com/news/corrosion-conference/Documents/CSC09-pdfs/PAPER_5D_GRUBB.pdf

 

[EdStainless]

Zecor and SX can only be purchased by the people that own the rights to them.
They are not generally available. I have made Zecor tubing in the past.

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P.E. Metallurgy, Plymouth Tube