Diaphragm Pump

[Amber Gold]

I think the pump is worn out on my filter press and am considering replacing it with a air operated diaphragm pump.

Does the castings need to be stainless or can the be polyethylene or maybe aluminum?

Are PTFE diaphragms good and what about santoprene? Are there other materials which would be better suitable for syrup.

As an example, this is one I am considering.

http://cgi.ebay.com/Sandpiper-Air-Operated-Double-Diaphragm-Pump-NEW-/280604580593?pt=BI_Pumps&hash=item4155561af1

Thanks

[Haynes Forest Products]

That pump is not food grade and will not take the heat:mad: I went to a supplier on Google and they said to call manf to spell out your specs:mad: And im not making fun about the food grade part.:)

[Haynes Forest Products]

Amber Gold Dang I think I would be looking at the Oberdorfers SS for what they want for SS food grade that will take heat:cry:

[jasonl6]

there is a used diaphragm pump on boscom's site for $250

https://www.bascommaple.com/item/c369/used_pumps/

Jason

[Amber Gold]

Isn't the PE body food safe? I'm not sure what temp. it's stable to though. The diaphragms are PTFE and the hardware is stainless.

Gear pumps are pretty expensive too and there's more to wear out.

jason, I saw that after I posted the thread. I think it's the same as the one I linked to.

[Haynes Forest Products]

Just because Bascoms sells it doesnt mean it can take the heat. I would start working the web sites for info direct from th4e manf.

[Amber Gold]

I'm going to contact sandpiper and get their input on it.

I was wondering what other's experiances are with using a diaphragm pump instead of a gear pump in a filter press. Is a 1/4" pump capable of pumping 4gpm going to be adequate?

[smitty76]

The reason they run a gear pump is to achieve consistant volume at high pressure, regaurdless of high temps. We all know why it is hot going thru the press, we can't change that. The temp part is going to rule out the diaphram pump. Also, it pumps what volume at what pressure. The higher the pressure, the lower the volume. I know, this is standard pressure vers volume stastitics, but an air operated diaphram pump slows way, way down when the pressure goes up way more so than other types of pumps. A gear pump will pump the same volume no matter what the pressure (to the limit of the pressure relief valve) as long as it is turnning the same rpm's.

[Haynes Forest Products]

I do get my motor to slow down but thats minimal. Now you must remember that an air driven pump will need a good compressor to keep up with the CFM requierments and high pressure to keep it up to specs.

[H. Walker]

CDL is going to have their own design and produced stainless gear pump out for this season that should be 25% cheaper than the Oberdorfer model. At that price the CDL model will be comparable to the diaphragm pumps and that's not taking in to account the diaphragm pump needs a large compressor to work. I'd wait until after Christmas when the new catalog comes out to check it out before buying any pump.