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98% Sulfuric Acid and 316 Stainless Steel Piping - Flow Rate Question

2007

Hello,

I am a mechanical engineering student currently on an internship and have been asked to look into the following scenario:

I am interested in the consequences of transporting 98% concentration sulfuric acid using stainless steel piping at a moderate velocity. Any input you can give me would be greatly appreciated and worthwhile to our project.

While I understand that it is advisable to keep the flow rate low (I believe for carbon steel, 3ft/sec is ideal), exactly would the hazards be if we were to increase our speed to, say, 10ft/sec? I am assuming that more air would be worked into the solution and thus diluting the acid into a not so safe concentration.

Would you happen to know any scenarios in which we would be able to safely increase the flow rate? For example, would lowering temperature of the flowing acid make it less likely to corrode a stainless steel pipe?

This is merely a theoretical situation right now, so temperature is independent at the moment. The only knowns are that the fluid is 98% sulfuric acid and the pipe is 316SS.

Thank you in advance.

Dominic Yeo
Student / Engineering Intern - Vancouver, BC, Canada

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2007

Hi Dominic,

Why stainless? Why not mild steel? Why not PVC ?
Why not lead? .... for min. 98% sulfuric

If 3l6L stainless, you sure are right by saying that a reduced concentration will attack it ! This applies, too, to mild steel but not to PVC nor, I think, to lead.

Velocity = pipe pressure increase

Also, think about welding it ! Will the weld possess the same quality as the metal? NO !

Go to the archives and have a look-see at 8698 and l5290

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).