vacuum filter setup

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That pump may not hold up long to acidic fumes, being cast aluminum the metal is very reactive, I am not sure what type of valves or what they are made of (possibly a stainless steel reed valves, or spring loaded ball valves as a guess, being advertised as oil less it may use a Teflon ring seal on the small piston.
Aluminum can passivate with concentrated nitric acid, so it may hold up to some nitric fumes but somehow I still wouldn’t think it would last long, the valves would have to hold up also, HCl fumes I am pretty sure it would not keep running too long.

Vacuum jar trap can help some to capture some liquids before they reach the pump, but under vacuum volatile liquid will boil at lower temperatures, even room temperature depending on the vacuum and the liquid involved.

There is not too much difference in a vacuum pump and an air compressor, or many mechanical pumps, basically a moving piston, or some other mechanism to compress air, check valves, reed valves or some other type of valves to move this air in and out of the pump, kind of like the engine in your truck, intake valves open to allow the air in as piston moves down to draw in the air on the intake stroke, as piston rises the intake valve or check valve closes, so air cannot go out the way it came in, and the exhaust valve (or check valve opens and lets air out the exhaust port.

A vacuum hose would hook to the inlet of the pump the compressed air hose hooks up to the outlet port of the pump.

To make a vacuum pump from an air compressor, you need to hook your suction hose to the air inlet of the pump, this may not be so easy depending on how the pump was made, and how the air inlet port is configured, you may have to Drill to resize an inlet hole and tap it for pipe threads, or build a small manifold for the inlet port and bolt it on with a gasket…

I cannot tell from the picture, where the air enters your pump or how the pump is made without having it here.

you may have spring loaded ball check valves inside the pipe (after where hose hooks up to the pump), I would unscrew them and check it out, and the port below (looks like it may be a valve) it may be the inlet port and may have another ball check valve, if this is so you might just be able to exchange these if the threads allow.

Have you considered using a Water operated aspirator with a trap for a source of vacuum?
 

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Thanks for the information Butcher. I've thought about the Water operated aspirator, but all my water pressure around here sucks...I can urinate harder and faster :lol:. I'll have to figure something else out, my wife would probably kill me if I modified the compressor as it is hooked up to an airbrush.
Rusty
 
Thanks Dave, just looking around trying to find something that I have that might work. Unfortunately I'm going to have to buy everything to build something. Your idea looks like it would work.

Rusty
 
Platdigger said:
Just a thought, but, how bout a small water pump (booster) to get the pressure you need to run an aspirator?

I've thought about that in the past, but we rent and the landlord won't do it. If anyone flushes in the house the taps slow way down.
 
The aspirators orifices are usually fairly small, which may help with your water pressure problem, I am unsure of your water source, but you could give one a try, I have found several aspirators, some nice brass ones in some old steam equipment I parted out, some plastic types at second hand stores, and where they sold second hand plumbing supplies.

If you have a well, the pressure problem could be a flooded pressure tank on your well, an easy fix.

Something you may want to try that work for a little while (be sure to use a trap and scrubber), is an old refrigeration compressor, I have made air compressors and vacuum pumps out of these (for other uses unrelated to acids or acidic gases which we have here), for a compressor or vacuum source these have worked very well for me for very long periods of time, one draw back of these for many uses is the move relatively low volumes of air but can achieve a fairly high pressure or relatively deep vacuum, (take some time to air up a big truck tire), after a fairly long use of one of these home made compressors, I will add a little refrigerant oil to it to keep it working, I have one I have used for about thirty years, when I built it I did not it to keep working for more than a job or two. Welding a handle to the top of the compressor can helps when you want to carry it around.

You might also look at your second hand stores, for some of those small 12 volt cheap air compressors they use to carry in your car to air up tires in an emergency on the side of the road, (very handy for that purpose carrying one of those, some bars to break a tire truck down and some patch kits have got me back on the road more than once). These will be similar to the small airbrush compressor you have now.

Check around, maybe you can find an old medical vacuum pump, these were very common.

Just save up for a vacuum pump better suited for the job.

Gravity can be awful slow sometimes, but in many cases it can save you money on a vacuum pump
 
hop on ebay and find a KNF neuberger w/ all PTFE heads and FEP diaphragms and call it a day or you will total your other pump rather quickly, or be changing a lot of oil!
 
Thanks Lou, looked that up, wow prices all over the place. Saw a few Laboport diaphragm vacuum pumps there and a few said chemical resistant. I'll have to remember that.
 
KNF, Vacuubrand, Buchi. Anything with a fluoropolymer internal will last you forever.

I think this is what we use at work:

http://www.vacuubrand.com/en/page984.html

Few months late, but we got rid of 3 or 4 KNFs that would've been perfect for you. Gave them away.
 
How about a fifty gallon barrel with a spigot at the bottom. The barrel is sealed except for a pvc tube at the top. If you put the other end of the tube on the stem of your vacuum flask and open the spigot on the barrel, as the water level drops in the barrel, it will create vacuum at the pvc tube. I think the strength of the vacuum would depend on the size of the spigot. You could catch the water in buckets and re-use it. Not the best solution, but inexpensive!
 
rewalston said:
I have a Badger Model 80-1 oil-less piston compressor such ask below http://i.ebayimg.com/00/s/MTI4NVgxNjAw/z/auQAAOxy4dNS9A3Y/$_57.JPG

I'm wondering if anyone would have any idea on how to convert it to a vacuum pump. Then all I need is a buchnel filter and papers. I have a flask already.

Rusty

Rusty,

I have been using this same vacuum pump for about 4 years.

It's seized up on me once because I did not change the oil for about 7 months, you should have seen the mess that came out of the oil sump. It looked vomit!

I removed two screws from the casing and gained access to the fan.

I put a vise-grip on the shaft and broke it loose and got the rotating assembly moving again.

Changed the oil and put it back in service. It's been running almost daily since then.

I even went out and bought a new one ( so now I have a spare).

I was trying to do a monthly rotation with the two pumps but I got busy and never did it.

It only cost about a hundred bucks at Harbor a Freight and It (they) have served me well.

kadriver
 

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kadriver, that is a nice looking pump. When I get back into recovery I'll have to look into one. Right now I'm not doing anything. No way to get scrap to work with. Blasted bylaws forced me to get rid of my truck that was 99% on the road. Wouldn't allow me to finish working on it (not allowed to work on vehicles in your driveway). And between them and my landlord I lost over $1000 between the truck and the brand new parts for it. So I'm just sitting on the sidelines reading the forum.

Rusty
 
I have a question what kond of pump should I buy for my setup? what parameters are critical to proper filtering? how many liters/min should have? one od two step pump? I'm using 2l flask with 120mm buchner funnel for filtration. Any advice appreciated since I've tried for testing an old vacuum cleaner - it works but poorly ;) I'm thinking about this kind for exaample: model V-i120SV http://www.worldvalue.cn/english/products-show.asp?type=&id=39
 
http://www.ebay.com/itm/1-8CFM-Single-Stage-Rotary-Vane-Deep-Vacuum-Pump-Refrigerant-AC-Air-Condition-/390788783877?pt=LH_DefaultDomain_0&hash=item5afcd39f05

Ive got one like this at the farm. I have been using it about 5 years now. I use the used motor oil i drain out of my car instead of that expensive stuff they sale. Never had a problem out of it. For $50 i can't complain and have sure made more than that from it. Kevin is right though drain it about every 6 months and get all the gross junk that gathers in the head out.
 
I'm telling yous guys, KNF or Vacuubrand. I know they're expensive, but we run ours literally 24/7 365 and they don't have oil back stream issues or waste oil to deal with...
 
Palladium said:
http://www.ebay.com/itm/1-8CFM-Single-Stage-Rotary-Vane-Deep-Vacuum-Pump-Refrigerant-AC-Air-Condition-/390788783877?pt=LH_DefaultDomain_0&hash=item5afcd39f05

Ive got one like this at the farm. I have been using it about 5 years now. I use the used motor oil i drain out of my car instead of that expensive stuff they sale. Never had a problem out of it. For $50 i can't complain and have sure made more than that from it. Kevin is right though drain it about every 6 months and get all the gross junk that gathers in the head out.

It's also a good idea to take the front plate off (left side of picture) and clean the housing out sometime.
 
On the exhaust hole get you a threaded pvc adapter that will thread into it. Add a 12-18 in piece of 1/2 pvc pipe running straight up toward the sky. This will give any oil mist a way to collect and drip back down into the pump as well as exhaust any fumes away from the motor to prevent corrosion from them being sucked into the motor and damaging it.
 

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