Greetings.
I have a need to replenish water in a high pressure hydrogen electrolysis system. The pump must overcome the pressure built up inside the system. (5000 psi.) I am using 1 meg DI water as my supply. The present system uses a 110 volt pump designed for spectroscopic applications and has a capacity of 500 ml/hr. Its finicky and the weak link in the system.
I'm looking for a pump which can deliver 1-2 gallons/hour at 2000-5000 psi.
What is available?
Thanks,
Tim

Fhis company makes Air Powered High Pressure pumpms in the low volume range you asked for.

http://www.haskel.com/

They have a couple of competitors also that you can find by Googling Air Powered Liquid Pumps

Thanks for the info.
I've been trying to avoid the air powered systems...just another component to malfunction and maintain. Do you know of any pumps that can be coupled to an electric motor?
I can easily control the power to the motor.
Tim

Try this type pump. It is te only High Pressure water pumps that I know of that are rotary. There are other manufacturers out there.

http://www.catpumps.com/

I hope you have deep pockets.

I agree with Bud's reply, that Cat pumps might have what you're looking for.
I served on NFPA's water hydraulics commitee a few years ago and learned that triplex pumps are used quite a bit in smaller water hydraulic systems.
Triplex pumps use a series of in-line pistons, with a crankcase that is oil lubricated.

Yes, Cat pumps work well in our pure water hydraulic power unit.

Yeah, I dunno about the cat pump (Im only adding my 2 cents worth) as The company I work for has been using these for some time on drilling equipment and I have to say in this application they arent as reliable as first thought.Though, your application it could be perfect."Bean" pumps are good option also..

The flow is quite low for the Hydrowatt pump but the pressure is right in line 3000 to 6000 psi. This is a rotary piston pump that is gaining traction replacing plunger-type pumps because of it's high reliability pumping dirty water. Unfortunately the flows range from 27 to 200 gpm.