Pumps

[Uncle Tucker]

I was wondering where I could get info on different types of vacuum pumps? There seams to be a lot of info on here but it’s all over the place. I am looking for details like: Which pump….

Produces the highest CFM
Produces the highest “ of Hg


What is the max CFM’s and “ Hg for:
Liquid ring with water
Liquid ring with oil
Diaphragm pump
Piston pump
Rotary vain with drip oilier
Rotary vain flood
Oilless rotary vain


If I find this info I will post it here for every one to help make future decision.
If any one can add to this I would appreciated.

Thank you,

[Maple Hill Sugarhouse]

post edited

[Uncle Tucker]

Thanks Kevin,

I was thinking of a post that people could do a quick reference when looking for a pump, or considering if a used pump will fit there needs.

[brookledge]

As long as the pump is in good condition most every one will give you the same amount of vac.
The key is which ones can handle it with out over heating and burning up.
Most of the liquid rings will give you the best performance under high vac.
The vast majority of producers however use rotary vane because they are readilly available since many dairy farms go out of business. However when used for milking you are under 15" so trying to crank up the relief valve to run them over 20" is going to cause them to heat up. Some have installed fans to blow air on them.
As for CFM's it's like a car engine they come in all sizes. The pump will have a rating for how many CFM's depending on how many rpm's and the amount of inches of Hg.
To size one for your needs figure 1 CFM per 100 taps and the rating has to be at the amount of Hg you are going to run it at.
Most vac. pumps are rated at "free flow" which is 0"HG them as you increase the Hg the CFMs drop. So becareful when sizing.
Keith