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View Full Version : Brass or Plastic


regularguy
09-26-2011, 11:32 PM
For pump impellers.

I believe that this subject may have been touched upon briefly before, but I guess that I am interested in everyones opinion on which is the best pump impeller material type for the money? I have a couple of the following pumps and one of them is in need of a rebuild.

http://www.wwpp.com/products/flint-and-walling-pumps/cjrepairparts.pdf

The pumps are Flint and Walling 2 horse 3 stage pumps and they came with brass impellers. The pump in question was torn down 2 years ago and I had a machine shop build up the impellers and I replaced the wear rings, it needs it again and this time I think I will replace the brass impellers, but there are 3 impellers and they cost about $125 each, with the rest of the stuff that brings the price of the rebuild to a little more than $500. Plastic impellers are less than half of the cost of brass and the performance is the same. I'm sure that they wouldn't last as long as the wear rings would still be brass, maybe the wear rings would last longer - that would be a good thing. I am concerned that the plastic impeller may wear out really fast and require much more frequent maintenance and in that case the savings may not be worth the hassle, but I am very interested in others thoughts and experience on this subject.

Wet_Boots
09-27-2011, 12:02 AM
how much sand are you pumping

regularguy
09-27-2011, 12:48 AM
how much sand are you pumping

I don't think I am pumping too much sand. The water comes from a series of shallow driven wells and I use smaller centrifugal pumps to draw the water from the wells and then pump it to the larger pumps to boost the pressure, the smaller pumps have plastic impellers and I have had them torn down before and was surprised at how little wear the plastic impellers had shown, that actually was what got me thinking about changing out the brass and switching to plastic.

jvanvliet
09-27-2011, 07:31 AM
I have centrifical pumps (Gould mostly, 1.5 HP & up) sucking (lots of dirty) water for years without wearing down the impellers, some as many as 20 years. I'd wonder what is wearing down your impellers that you need them built up after a couple of years.

regularguy
09-27-2011, 11:30 AM
I have centrifical pumps (Gould mostly, 1.5 HP & up) sucking (lots of dirty) water for years without wearing down the impellers, some as many as 20 years. I'd wonder what is wearing down your impellers that you need them built up after a couple of years.

The pump is probably ten years old and a couple of years ago I tore it down and had the impellers built back up and replaced the wear rings, at that time it was in pretty rough shape and showed a lot of wear. I had a machine shop do the brass work and I'm not sure that what I did was the best way to do the repair, I always thought that it was a little louder when it ran after that. I guess that I got about 8 years out of the pump when it was new, I thought that was a pretty acceptable life from the pump, I don't utilize a flow meter but my irrigation software calculates water useage based on flow multiplied by time and I usually average about 1.5 million gallons per year, some years more and some less based on the weather.

jvanvliet
09-27-2011, 05:12 PM
The pump is probably ten years old and a couple of years ago I tore it down and had the impellers built back up and replaced the wear rings, at that time it was in pretty rough shape and showed a lot of wear. I had a machine shop do the brass work and I'm not sure that what I did was the best way to do the repair, I always thought that it was a little louder when it ran after that. I guess that I got about 8 years out of the pump when it was new, I thought that was a pretty acceptable life from the pump, I don't utilize a flow meter but my irrigation software calculates water useage based on flow multiplied by time and I usually average about 1.5 million gallons per year, some years more and some less based on the weather.

I wouldn't complain about eight years, I thought you said you just had it done about two years ago.

Anyway, we run the water all year long and I haven't had to replace or rebuild any impellers... yet (motors yes, impellers no) and we suck a lot of dirty water.

I'm still wondering what abrasive is suspended in your source that would wear down an impeller in two years, and a brass one at that. I'd check the well, down here shallow wells are dirty.

Don't want to get into a pi$$ing contest at all, I'd look at the source and maybe consider a self cleaning particulate filter. Somebody on here had a link to a submersible type, maybe he'll post here.