galvanic corrosion- sulfuric acid- wear ring

[apadana]

Dear All,
We are going to prepare a Material Requisition for a centrifugal pump for concentrated Sulfuric acid, (>98%) unloading application. Per API 610 standard we had specified Class S-1 material. The client has called for stainless steel (304) for case and impeller wear rings. I am wondering if there is any risk of galvanic corrosion between the wear rings (stainless steel ) and the impeller or case (Carbon Steel or Cast Iron) ?
Thanks,

 

[EdStainless]

One of the reasons that concentrated acid is not very corrosive (as compared to mid-range) is that it is a poor electrolyte. It is not a good electrical conductor, and this reduces the risk of galvanic corrosion.
Are you using a high Si cast iron? While standard ductile iron has decent corrosion resistance in strong acid you have to watch for the velocity effects. Your material selection does not look to be sulfuric acid specific.

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P.E. Metallurgy, Plymouth Tube