Sciencemadness Discussion Board

Modify compressor to vacuum pump?

nannah - 9-10-2014 at 11:00

Hi guys. I have an old compressor that i want to modify so i can use it as a vacuum pump. I just have to say that its not an fridge compressor pump.

Thanks in advance. :)

Marvin - 9-10-2014 at 14:35

Entering into new levels of vague is always difficult. Clearly you've searched the forum and found what questions were successfully answered in the past and then avoided those errors. Your only major mistake was telling us that it isn't a fridge pump, which narrows possibilities. We have no idea what you want it for or what skills or tools you have, so that's good.

On a scale of
0 (Easy to answer and no more information needed to do so)
to
10 (Impossible to answer, question contains statements that cannot be meaningful simultaneously)

I give your question a 6.

To move to a 7 or 8 you'll need to stretch your imagination a bit. Think compressor to an artificial heart or holographic TV.

Mesa - 11-10-2014 at 04:22

I believe he is talking about an air compressor i.e. for spray guns.


violet sin - 11-10-2014 at 04:56

which come in hobby size air brush to several hundred PSI multi-gallon air tank construction versions for spraying houses. one with an attached tank for storage and high volume air, and one for on demand low volume air( air brush pump). so the point has merit.

but here is one fix for 12v tire pump: kinda messy
http://www.instructables.com/id/convert-a-tire-inflator-type...

another one for a similar machine that is a bit easier
https://www.youtube.com/watch?v=uyG2_-QNjZY

this one is for a craftsman job site kind of compressor:
http://forums.bimmerforums.com/forum/showthread.php?1210620-...

but they all revolve around finding the air intake and attaching a hose barb and hose. but in the craftsman version with attached tank, you might want to remove the bottom plug completely unless you want stuff congregating in there.

CuReUS - 11-10-2014 at 05:38

read this book it might help you ;)
https://parazite.pp.fi/Nimble.pdf

jock88 - 11-10-2014 at 12:28

A refrigerator pump IS a compressor.
See the thread called:

Let the questions on the refrigerator compressor being used as a vacuum pump commence and never stop. :P

Its a sticky at the top of apparatus and reagent aquisiton

[Edited on 11-10-2014 by jock88]

Mesa - 12-10-2014 at 08:47

Quote: Originally posted by violet sin  


this one is for a craftsman job site kind of compressor:
http://forums.bimmerforums.com/forum/showthread.php?1210620-...


I've done exactly this modification with my 2.5hp 40l compressor, I found a drain cleaning tool which happened to have the same thread as the filter housing, and used tubing the exact diameter required to fit the barbs on my own glassware.

I've still not figured a safe way of testing it out yet however.

jock88 - 13-10-2014 at 12:39


When is the maximum load on the motor of the Vacuum pump?
Is it when there is little or no gas going through the pump or when it is open to the air.
The pump that I have is a Welch duoseal. The manual states that if it is run open to the air or of a large leakage of gas is going into the pump (working above 20 microns or so) the pump will get hot.
From my experience there is less load on the motor when the pump is open to the atmosphere and when you close it off (I have not measure the vacuum) the belts start show more strain. The half horse motor I have is not fit to run the pump when it is closed to the atmosphere (pulling a vacuum).
Why do they run hot when open to the atmosphere. You would imagine there is less load on both pump and motor and air going through the pump would help to cool it anyways?

j88