SpudFiles

Well, for my science fair project, I realized that I will end up needing some rather high pressure fluids. Specifically water and gasoline. Fuel Injector pumps are f*cking inexpensive, and I don't quite need 29,000 PSI.

Does anyone know of an available, inexpensive type of pump that would be able to pressurize liquids to 700-1000 PSI. Flow rates are minimal, only about 300 cc/min. A shaft driven or electric driven pump would be ideal.

I was considering a power steering pump, but those probably depend on the power steering fluid for lubrication.

How would a fridgy hold out pumping liquids across this differential? Excess flow would be diverted back to the inlet. Lubrication is another issue.

Define inexpensive.

Diesel injection pumps will make the pressure you're after, but I suspect those are the ones you found expensive as well. Gasoline fuel injection pumps don't make near that pressure.

Do you need constant flow and pressure?

Plunger style pumps will pump anything, but ... not constant pressure.

Pressure washer pump?

Build it yourself? Typical chemical injection (plunger type) pump. Simple stuff.

http://www.bruininstruments.ab.ca/br5100/assem_dwg.htm

DIY shop -> Pressure washer.

About as low cost as you can get.

Could you describe this experiment for those inquisitive members like me?

direct fuel injection (sorta). It's more of an engineering project than an experiment.

Diesel injection pumps are what I considered "expensive"

I considered a pressure washer, but I'm not sure that would appreciate being fed gasoline (wasn't there a thread about that recently )

I can use an accumulator to even out pressure, so a plunger style pump may work. Any idea regarding O-ring lube that will survive in a gasoline environment?

Flourosilicone, viton or teflon for the seals.

Teflon is self lubricating...and can be machined to make new seals for a pressure washer pump...


TCG (Teflon Carbon Graphite) is my favorite material for dynamic pressure seals.

Material compatability ...

http://www.hitechseals.com/chemical-com ... cal_id=939

If you do modify a pressure washer pump, you will need to design with flammable fumes in mind at the pump. This would mean using enclosed spark proof electric motors, contractors, switches, etc to prevent a pump fire.

For lower volume, a direct drive brush less (electronic drive) airless spray paint pump may do the trick with replaced seals as mentioned above.

Some are compatible with oil based paint, but most are for water base Latex paint.

A ready made solution may be to find someone discarding an old oil furnace. The pump in those are high pressure, pressure regulated, and designed for flammable liquids.

on backyard metal casting one guy used a fridge to pump oil for a furnace, idk about petrol.

A vane pump does OK with liquids. A piston pump doesn't work too well. Check which style it is. Both are positive displacement, so a bypass relief valve to prevent stalling is recommended.

ramses wrote:Well, for my science fair project, I realized that I will end up needing some rather high pressure fluids. Specifically water and gasoline. Fuel Injector pumps are f*cking inexpensive, and I don't quite need 29,000 PSI.

Does anyone know of an available, inexpensive type of pump that would be able to pressurize liquids to 700-1000 PSI. Flow rates are minimal, only about 300 cc/min. A shaft driven or electric driven pump would be ideal.

I was considering a power steering pump, but those probably depend on the power steering fluid for lubrication.

How would a fridgy hold out pumping liquids across this differential? Excess flow would be diverted back to the inlet. Lubrication is another issue.

I would suggest the power steering pump to be honest with you. I have done a few steering repairs and the parts are pretty simple. The power steering fluid is just hydrolic fluid. Even if you weren't going to use the fluid I am sure the pump would hold up. I saw one on a honda civic that had been running dry for 10k miles and it worked just fine when we put fluid in it again.

MadPiper2.0 wrote:
I would suggest the power steering pump to be honest with you. I have done a few steering repairs and the parts are pretty simple. The power steering fluid is just hydrolic fluid. Even if you weren't going to use the fluid I am sure the pump would hold up. I saw one on a honda civic that had been running dry for 10k miles and it worked just fine when we put fluid in it again.

Thanks. My concert is that the gasoline (or petrol, for you Brits) would actively dissolve any residual lubricant that might be needed for it to seal. Would a vane pump work with such a non-lubricating, non-viscus fluid?

Tech, is this what you had in mind? or something more costly. I am aware that the flow rate is inadequate.

Thanks!

I had in mind the one that sits on a 5 gallon bucket. The solenoid models are inadequate. These are generally between 1/2 and 1 HP.

It will meet your pressure requirement. Specs on one model is;

Wagner Airless Double Stroke Piston Pump Paint Sprayer Model 9175. Spray up to .35 Gallons per minute. 0 to 3000 PSI. 3/4 HP Motor.

This exceeds your flow requirement also by about 4X.
Amount : .35 gallon US / minute (gal/min)
Equals : 1,324.89 cubic centimeter / minute (cm³/min)

poop. That still leaves me with about $800 in pumps.


I'll monitor ebay. Are induction motors considered non-sparking?

Induction motors with a start switch in them are spark producing as the start switch operates. Low starting torque motors with a run capacitor or shaded pole are not spark producing. These are often used on low starting torque applications with a large inertial load such as fans.

For fuel use, fully enclosed motors are recommended.

3 phase motors are not spark producing as they don't use a start switch.

ramses wrote:

MadPiper2.0 wrote:
I would suggest the power steering pump to be honest with you. I have done a few steering repairs and the parts are pretty simple. The power steering fluid is just hydrolic fluid. Even if you weren't going to use the fluid I am sure the pump would hold up. I saw one on a honda civic that had been running dry for 10k miles and it worked just fine when we put fluid in it again.

Thanks. My concert is that the gasoline (or petrol, for you Brits) would actively dissolve any residual lubricant that might be needed for it to seal. Would a vane pump work with such a non-lubricating, non-viscus fluid?

Tech, is this what you had in mind? or something more costly. I am aware that the flow rate is inadequate.

Thanks!

You could mix in some oil with the gasoline to seal and lubricate like in a 2 cycle engine. It will burn off into blueish smoke after combustion. I really wouldn't recommend putting that kind of pressure on a petroleum based fuel. It's likely that the compression could cause spontaneous combustion. Sometimes in gasoline engines if the spark plug doesn't fire, the compression cycle alone can cause detonation.