Selection of Impeller material
Selection of Impeller material
(OP)
I have a discussion with some engineers regarding the selection of the impellers material for horizontal booster pumps that will be used to pump clean water, with the possibility to have small debris passing through the pump (like sand and silt).
The selection is between Cast iron and Bronze impellers, Bronze doesn't rust but cast iron does, BUT at the same time the impeller material must be chosen for both chemical compatibility and wear resistance so we may need to consider one of the duplex metals because most corrosion resistant materials are too soft for the demands of a pump impeller
From your experience with impellers material selection, what would be the best choice for the pump impeller? Is it bronze which is soft or the cast iron which will rust??
We are in the process of finalizing the technical specifications for the required pumps. Your inputs for the disadvantages and advantages of both choices are highly appreciated...





RE: Selection of Impeller material
would prefer bronze if any salt (sea water is involved)
RE: Selection of Impeller material
Steve Jones
Materials & Corrosion Engineer
http://www.linkedin.com/pub/8/83b/b04
RE: Selection of Impeller material
The correct selection depends on the water chemistry (as already noted), the exact composition of any solids, the flow velocity, etc. If I had to pick a readily available, hard, durable material with good corrosion resistance, I would choose CA6NM (11-14% Chrome). But, for a very large impeller, this could be extremely expensive. If the velocities are relatively low, I would tend to go with bronze as my next choice. I would only select stainless steel (316) if there was an overriding need that could not be satisfied with the other options.
Johnny Pellin
RE: Selection of Impeller material
RE: Selection of Impeller material
RE: Selection of Impeller material
If the sand content is negligible - bronze is the best answer.
RE: Selection of Impeller material
I agree with the comments that for common service Bronze is a good choice. With CA6 being an upgrade from there.
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Plymouth Tube
RE: Selection of Impeller material
I am curious about your "austenitic cast irons"
I have never heard this before. Can you give us more details ?
Perhaps an internet reference ?
RE: Selection of Impeller material
RE: Selection of Impeller material