FMI Small Displacement Pump

[rtp_burnsville]

Hi Guys,

Just wondering if any of you have built a pump similar to these:

http://www.fmipump.com/

They look amazingly simple except for maybe the motor to pump joint as I have not found a good photo of that portion.... What materials would you recommend? I would like to make something like this for a micro-drop coolant system.

Thanks,
Robert

 

[shred]

I'd guess the close-fit ceramic material may be important for dimensional and wear issues (like kitchen faucets are mostly ceramic cartridges), but it's not dissimilar in operation from several of the valveless engines

 

[Ed T]

I looked at this kind of pump for an application I was working on several years ago. I'm not sure what you plan to do with it, but it is principally intended as a metering pump as opposed to a pressure source. Ideally, in a metering pump there is no pressure differential between the inlet and the outlet. In the real world there is some differential, but it is, preferably, minimal. The fit of the cylindrical parts is important to avoid leakage between the piston and the cylinder. That is one of the reasons they use ceramics as they are dimensionally very stable and can be machined to remarkably tight tolerances w/o the issues that affect metals like thermal expansion due to heating from cutting. I think there are a couple of other companies making similar pumps so you might want to search around a bit and maybe you can learn more about the details. It is, if nothing else, a very elegant concept.

 

[rtp_burnsville]

Thanks for the response guys.... I did note the original uses a ceramic piston, have not worked with ceramics so thought I would try drill rod as a starting point.

My plan is to meter a low pressure fluid into a similar pressurized output so don't think there should be a problem with the pressure differential. However, thanks for noting that issue.

I have searched but did not find any similar pumps.... If anyone has a name that would be helpful.

Thanks,
Robert

 

[Ed T]

IVEK is one