Sciencemadness Discussion Board

Harbor freight rotary vane vac pumps $75-90...

evil_lurker - 5-8-2008 at 19:58

I dunno when the heck they got them in, but they got 2.5CFM rotary vane pumps for freaking $90 and if thats too much they have the 1.2CFM pumps for $75.

At that price they are practically disposable... if you could get an extended warranty on them, they would be gold.

kclo4 - 5-8-2008 at 20:07

Wow! Great find, thanks for letting us know about it I might have to get one haha

evil_lurker - 5-8-2008 at 20:09

This would be perfect to run a cooling system too:

franklyn - 21-5-2010 at 17:15

Manual here _

On sale at Harbor Freight just this weekend
Click the picture at top here to go to the coupon page
and " click here to buy on line " on the coupon

Click on " add to cart " then in the next window add coupon code
to receive the $ 10 discount , as explained here _

FED-EX shipping is about $ 10


Chainhit222 - 21-5-2010 at 20:38

are these pumps teflon coated by any chance?

Sedit - 22-5-2010 at 06:09

Being frm harbor freight it better be disposible considering its more then likely going to break a week or two from now like many of the things you buy there.

Still its a good deal and it only gets better. Iv seen these there for sometime around my parts and if you can get it when its on sale you can knock another 20$ or so right off that price. I have seen them for around 50$ before. Iv always been hesitant to purchase one because even with howmuch I love harbor freight there tools don't exactly have the best track record in my book.

beastmaster - 10-6-2010 at 17:45

I just bought one for 79.00 plus 25.00 for the two year extended warranty. Haven't used it yet, but they honor their warranty. You can run it over with a truck and they will replace it. Its a 2.5 cfm. How can you go wrong at that price.
It's my first real vacuum pump.

quicksilver - 11-6-2010 at 06:44

I don't want to rain on anyone's parade here but their 2 stage pump MAY survive the manipulation of caustics and acid fumes because it separates what it's pulling from the driving vane. The little $69 pump really won't survive. A better bet is to buy a $29 vacuum cleaner at Home Depot as no metal would be exposed to caustics. And there you have a real disposable unit.
I have used very high quality lab-level vacuum pumps that eventually bought it from being used in acid distillations. This single level pump will most likely give service for a few distillations IF you run water through it right after use but likely as not, it won't stand up as long as their two stage pump (because that one is made for pulling refrigerant gases, not fluids). Even the two stage pump is questionable: not because of it's strength but it's "low-bid Chinese slave-labor" manufactured. But if it's really cleaned out it might hang on. NOx gas is really nasty. The vanes may stand up....but not the metallic components & housing. Most of the time, you really do get what you pay for.

gtchemen - 11-6-2010 at 08:06

i have one off auction that looks just like it. got a 5cfm for $100 about including shipping

THis thing isnt that good.. Its single stage. It seems to lack power after a few long distilations and the worst part of it is that its messY!!!.. its shooting freeking oil mist that looks like smoke.. everywhere!!! its like amazing how crappy this thing can be... it works but... i dont know how long its got left..
i mainly used it for distilations and i put alot of oil in it but the performance seems to be lacking.

spend your money on something for worthwhile!

densest - 11-6-2010 at 10:23

Tips for using rotary vane pumps:

They make oil mists when pumping large volumes of air. Either put a mist catching filter on the output (McMaster Carr has them for $12 or so) and/or put a valve in series in the input line. Close the valve, close the thing to be evacuated, start the pump, and -slowly- open the valve to evacuate your system. You do have a valve to slowly bleed air into your system when you're done, don't you?

The oil must be replaced when contaminated with water, acid, or solvents. Performance drops remarkably with contaminated oil, followed by pump failure. Sludgy oil is a huge load on the motor.

Protect the pump with traps on the input line. A simple empty trap will catch a lot of liquid. A trap full of soda-lime will catch acid. Fine glass wool will catch particulates. A cold trap will catch water vapor. While the pump may be $50 and the traps may be $30, if your time is worth anything the traps pay for themselves very quickly.

There 's always Ebay

franklyn - 11-6-2010 at 19:46

For a pig in poke.

Rotary vane vacuum pump

Rotary vane vacuum pump.jpg - 86kB

zed - 12-6-2010 at 04:30

Jesus, a good vacuum pump should last twenty years or so. Clearly these aren't high quality pumps, but if you use them without traps, you are making them worse than they are. They aren't built to resist corrosive chemicals.