looking for a pump that I can hook up onto a pneumatic motor

[CamTheNewby]

i want to make a system where I create a steady pressure of approximately 60-100 psi of pressure. I want to buy a pump (i'm thinking a diaphragm pump), as well as a pneumatic motor and also maybe a check valve that would work in that pressure range. Possible? Any help would be great.

As a specific question, I am wondering (based on the specs listed in the doc listed below), how I would find the fluid pressure that this pump would be able to output.

http://www.all-flo.com/pump-sizes/quarter-inch-pumps/Polypropylene/bk-025.html

 

[MikeHalloran]

You need an air compressor to run that pump.
Feeding it 100 psi air will allow it to develop 100 psi on the liquid side, at zero flow. Allow a little flow on the liquid side and the liquid pressure will fall, along the curve provided in the data sheet.

It's not clear what you intend to do with a pneumatic motor or a check valve.


Mike Halloran
Pembroke Pines, FL, USA

 

[CamTheNewby]

well, I want to create a deadhead situation ideally, but I think that I will require some flow. Maybe one gallon per minute. I want to spin a rotary valve and test its performance capabilities. I want to test it for a long period of time. The rotary valve has a 1.6" diameter inlet and outlet. We are going to spin it, and test the seal drag on the seals located within the rotary valve. Do you know if my outlet valve should match the diameter of the pneumatic pump? This one seems a little bit closer to the same diameter as my inlet / outlet valves.

http://www.ingersollrandproducts.co...expert-series-pumps-exp/1-1-2EXP-Non-Metallic

 

[MikeHalloran]

What outlet valve?

What turns the valve you are testing?

The pumps you keep proposing are used to transfer chemicals from a barrel to something else. There are no rotating parts within them. There are no moving parts exposed. They don't operate continuously; you apply air and the pump goes burp-it-a-burp-it-a-burp-it-a-burp-it-a and the chemical squirts out a little at a time. No part of its operation is 'steady' in any sense of the word.





Mike Halloran
Pembroke Pines, FL, USA

 

[tbuelna]

If you want a steady flow of fluid to your test valve, does it need to be at 60 psi or 100 psi? It makes a big difference in the amount of power required to drive the pump if the circuit pressure is 60 psi or 100 psi. Also, if the fluid flow is variable, you will want to use an accumulator in the fluid circuit.

 

[LittleInch]

Cam,

I'm taking a guess that this is closely linked to your previous post - here for anyone who wants to check it out -

http://www.eng-tips.com/viewthread.cfm?qid=364809

-. For me I think you need to first work out what you want the flow to do and then choose an appropriate pump rather than try and choose a pump for an unknown duty.

From what I can gather you want to have 100 psi in a no flow situation, presumably as a pressure differential, i.e. 0 psig on the far side. Then you want to open and close the valve lots of times. However it is unclear if you want a certain flow through the valve before it closes or what. It would be very good for you to think about the flows and pressures in this period.

The issue is that if you dead head a pump then open the discharge but to a very low pressure drop you would get a v high instantaneous flow before it decays to the steady flow the pump is capable of. These are the properties of a PD type pump, but I would choose a pulseless type such as a gear pump or similar, not a diaphragm unit or similar which is highly pulse driven. You need a fixed flow through the pump and with a pressure relief valve this can be established and then flows through your valve before you turn it off again.

Alternatively have an accumulator and d/s of the valve introduce some sort of restriction (orifice, control valve etc) such that the flow rate is limited once your valve is open. An open pipe back to the sump tank would provide only low pressure drop and hence potentially very high flow before you turn your valve off.

When you work out what sort of flow and pressure you want across the entire on/off cycle then you can find the right pump.


My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way