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Polypropylene vs. PVDF for impeller of magnetic pump

2007

Our plating line is pure tin plating (contain MSA, tin and organic at 20 °C).
Sometime tin crumb from plating bath enter in impeller of plating pump and make it dirty and broken. Which material is suitable for impeller of magnetic pump ?
We need suggestion about polypropylene & PVDF material in impeller magnetic pump.
Which one is the best between polypropylene or PVDF. What is advantage or disadvantage between those material.

Alidah
electronic - Lobam, Bintan, Indonesia

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2007

Hi Alidah !

PP or PVDF? PP is fairly good in acids and pretty good in alkalines. Also MUCH cheaper than PVDF.

PVDF will accept much higher temperatures than PP ... 140 to 80° C ... superlative in acids ... poor on strong alkalies of over l0.5 pH.

Solids hitting the pump? The answer there is to use a line strainer ... ideally a real oversized one (Why? because it will take much longer to plug up) AND a Tee with a pressure gauge so that you can SEE if the strainer is plugging up. But as pumps don't like to run dry, then CHECK that pressure gauge often, OK?

Lastly, I'd imagine that a PP or a PVDF pump would also have the casing in that material, ergo it will cost you much more for PVDF ...

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

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Polypropylene is used in the majority of metal finishing applications - some Polypropylene used by pump manufacturers has a glass fibre filling in the material, which is often cause of premature failure on an number of applications such as Nitric, Hypochlorite etc.

Check to see what you are pumping, if we have any suspect liquid to be pumped, we upgrade to virgin ETFE material as standard - it's not that much more expensive than what you may imagine !

AshleyFenn
pumps - Northants, England
2007

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Hi Ashley,

Re pump materials, why not use good ole CPVC ... quite common in the USA but I don't think that we have any plastic pump mfgrs in Canada.

It's acid/alkaline resistance is far better than PP, more so where oxidizing liquids are used. And would be far less expensive than ETFE, methinks.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).
2007