Hydraulic pump as a water pump?

[[XC] gomeler]

I'm still searching for a water pump that will be able to pump ethanol at ~-80 Celsius and I started thinking about oil pumps. Looking around I then got sidetracked reading about hydraulics and then thought maybe a hydraulic pump would work. I figure since it's made to run stupid high pressures it must be piston based rather than impeller based which is what I need since I'll be pumping a liquid with the consistency of maple syrup.

Now my question is.. does anyone have any experience with hydraulic pumps? Can I use a higher displacement hydraulic pump and run it at a modest speed like a water pump? Cheapest high displacement pump I can find is a .97 cubic inch per rotation pump with a 2000 RPM optimal speed which would yield ~480 GPH.

These pumps tend to be paired with 5 to 10 horse power gasoline engines. I suspect all this power is needed to overcome the enormous pressure differential, can anyone confirm this? If so I would say maybe I could use a 1/3hp 110vac motor with pulleys and a belt.

Need help here.. no experience here so I'm just shooting blindly.

[[XC] gomeler]

Seen a few hydraulic pumps that look like they must be vane pumps due to the way they are plumbed. By relief spring do you mean having a sort of blow-off valve/by pass to keep the pump from boosting pressure with what little restriction there'll be in the loop?

[[XC] gomeler]

found my liquid pumps :up: manufacturered by procon, 140gph vane pumps. Not as high flow as I'd have liked but they'll suffice :)

[link1896]

I've worked with a few different style pumps for non pc water pumping loops (laser cooling, electronics cooling, welding equipment, etc)

Vane pumps are notorious for the carbon brush material getting into the fluid being pumped.

Any "hydraulic" pump, be it vane or gear that is designed to be pumping oil will not last long pumping a non lubricating fluid like water/glycol or ethanol


some gear pumps, or diaphragm pumps are suited to pumping coolant in a pc loop. For -80c, diaphragm pumps are out. I'd be looking at gear pumps

I've serviced gear pumps that used oil seals for shaft seals, and delrin journal bearings that have been going for 30,000 hrs so far, with bronze gears, that are pumping a water/glycol mix.

I'm really not a fan of centrifugal pumps, Cheap, but often used a fair way off their best efficiency point.


For a gear pump to do -80c, it will need proper carbon/ceramic mechanical seals and not a rubber shaft seal.
Avoid this seal (http://www.germes-online.com/direct/dbimage/50334762/Oil_Seal.jpg) and look for these (http://www.rocketseals.com/assets/244/mechanical-seals-imageok96o1_preview.jpg)


as an irrelevant side note, I've a nice diaphragm pump I've been using for testing, does 11 lpm at 28meters head! runs from 12volts, so I've a variable dc supply based around a pc power supply. When ready I'll throw up a clip of a swiftech storm with a diaphragm pump, its quite amazing.

[XS_RoB]

link1896 - I'd be interested in getting the results from your test. Do you have a link to the pump your speaking of?
Thanks

[link1896]

link1896 - I'd be interested in getting the results from your test. Do you have a link to the pump your speaking of?
Thanks

very similar to this (http://www.flojet.com/products/industrial/construction_machinery/quad_dc_pressure_controlled_pump_4300_series/iid_1988/index.htm)