Engine with steel pistons?

[digsaw]

What about a marine submersible electric builge pump, or a nitrol impeller pump used for pumping sea water used for engine cooling in boats.

[Flyingpony]

How about an older style water pump from a car?

Have you thought about using Gravity in your design?

[Smokin]

We have pnumatic diaphram pumps at work that are used for pumping anything, waste oil, glue and timber treatment. They have a plastic body with a rubber diaphram, they have a very good flow rate but a bit low on pressure side of things.
I can get you a model name tomorrow if you want?

[cowpoos]

Sotty guys... I have a job too 9apparently) which takes me away from my work here at KB..

Pumping oil with Caustic Soda (NaOH) in it as part of making BioDiesel. I can move a little bit from A to B using a power steering pump but it has Aluminium bits inb it which get eaen by the NaOH... hence my requirement for Steel (or Stainless or Teflon or HDPE...)

It struck me that an engine with suitably protected pistons would do the trick.

I've had all the conversations about head flow characteristics of pumping liquids, and bypass of the ring polluting the oil etc - those problems are solved... the pain in the butt issue is currently finding a piston (and crack and bore) that does not involve Aluminium...

To put it in context - I'm looking to pump 50 litres a minute (initially) then more... so we're talking 50 RPM from a 1 litre motor... that's less than one rev per second.

Hope that helps... now... back to where I was... positive displacement pumps without any Al in them... (watch out for housings... they're most often Al too... dammit!)

go to a milking machine company and get a ex-cowshed diaphram pump....has rubber diaphram...completly okay for oils and caustic soda...we wash our plants with caustic soda so sweet as....will be cheap as chips cause they arn't used on new plants...it will work a treat and solve ya problem!!

[MikeyG]

Like poos says go for a diaphragm pump. They are used for pumping caustic in diary sheds, dairy factories, sewage treatment plants and water treatment plants. Air or electricity powered ones are available off the shelf.