Hmmm. 20 watts 5 L/m is going to be tough.

Shurflow pumps take a lot more than that. We do a peristaltic which will do 1 L/m at about 12-15w. (we do have some 24v motor/gearbox aassys too although they are non standard.)

What sort of duty cycle are you after? A peristaltic won't want to run continuous, say a few hours a day would be ok, else you will be constantly changing the squeeze tube.
Can you put up with a slower delivery?

Del

Hi Del,

Thanks for the quick response. The duty is likely to be about 8-10 hours/day intermittent operation with the pump turned off overnight. I was hoping to find a pump that didn't need regular servicing. Up to 30W would be OK, and down to 4/L a min could also be acceptable, but these are the max/min limits.

DE

Seko have a presence in UK they do good diaphragm metering pumps but I think they are mains driven...they will run ad nauseum tho' and are accurate and easy to set up.

Or maybe shurflow.... they do DC stuff but it's quite high current.

I'd rule out peristaltic on duty cycle/tube life grounds.

Del

Automotive fuel pumps are what you need, they are cheap and reliable. they use very little current if you are not lifting far and at nil pressure. They are also designed for continuous running. You can either get 24v or 2x12v in parallel

But they won't pump 5L/min I wouldn't think!!!

don't pump liters then pump gallons.

WAIT!

Now if it needs to run 8/10 hours that means while your pumping the tank is being filled? right.

If so. run the oil straight into the tank your filling.

can you use a

A peristaltic pump might work, though the temperature spec is going to make the tubing choice a tricky one.

Watson Marlow (usual disclaimer)?

What peristaltic pumps manufacturers are used in blood and dialysis applications?

You may wish to search "metering pump" or "acid pump" which is what we used them for. I think they were 115VAC which a UPS and ground fault outlet can create.

Years ago Grundfos made Stainless HVAC circulating pumps for boiler systems, various flow and head capacities.

You may also wish to look at a boat bilge pump, which will run on 24 VDC.

Or a diesel engine may use a fuel pump that is 24VDC and low quantity.

http://flow-control.globalspec.com/SpecSearch/PartSpecs?PartId=%7BB6669673-1BF0-4D17-9965-14C564B34B45%7D&VID=134989&Comp=3943&QID=11099756

http://www.clarksol.com/html/prodspecsM3000Pump.htm

It looks a bit difficult to meet your 20W requirement, which seems a bit strange as you're actual (output) work rate is less than a Watt. I suspect that most pumps in this category would push the liquid up much more than a meter.

Not sure if this :- http://www.clarksol.com/html/prodspecsEMX08Pump.cfm

With a DC adapter board:- PD-106 DC

meets your other requirements; could be worth ringing them.

I'm very suspicious of the fact that they seem to be selling a diode which is part of the electrical design separately.

I think I'd be tempted to replace that 3 Amp diode:-

http://cpc.farnell.com/SC05622/components-spares/product.us0?sku=multicomp-1n5406

with a 6 Amp one:-

http://cpc.farnell.com/SC05939/components-spares/product.us0?sku=multicomp-p600k

Perhaps I'm just reading something into their "price list" which isn't there .

Hi Randall,

Thanks for thie input.

The M3000 range looks a bit too big and consumes 100W on DC.

The EMX08 looked more promising, but unfortunately it can't take the temperature.

Thanks again for your suggestions.

DE

Try one of these.

http://www.northerntool.com/webapp/wcs/stores/servlet/NTESearch?storeId=6970&N=0&Ntk=All&Ntt=d/c%20pump&Nty=1&D=d/c%20pump&Ntx=mode+matchallpartial&Dx=mode+matchallpartial

Hi DW5B,

Unfortunately the flow rates for these pumps are much higher than the rate I require. The main focus of the requirement is acheiving the duty with minimal power.

DE

I was told once if the problem is taking more time to solve that is should CHANGE THE PROBLEM.

I would made a change that would adapt one of the affordable pumps to needs.

maybe this puppy would fill the bill.

http://www.pumpbiz.com/products/index.cfm?fuseaction=pump_model_detail&product_id=6206&series_id=296

24V 10W 3 gpm TDH 4ft, the only question mark is the silicone elastomer. Not sure if that is compatible with Veg. oil. but I'm sure that March can make a version with Viton seals if you contact the manufacturer directly.

Can ask you to look up condensate power pump Model APT of Spirax Sacro or the one with an ss body to pump this 100C vegetable oil but only with air/steam as motive. Very low in energy and virtually maintenance free. Will pump when there is something to pump.