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pntrbl
11-11-2007, 11:25 AM
I'm working on pressurizing the coolant tank I use on my Noga Mini-Cool. Because I like the convenience of using the air shut off right there on the mister, I thought I'd plumb air back to the tank from the mister body itself. There's a extra 1/8" NPT port on the body of the thing just waiting for me to make use of. After some dedicated phone work I located a Noga air line from Wholesale Tool for $11. I think I'm all good on this part but feel free to comment ...

Not seeing a good way to introduce a needle valve into the coolant feed line, it occurred to me to put a valve into the aforementioned "air to tank" feed line. I'm assuming I'll need less pressure in the tank than the spray tip by setting it up this way (could be wrong), but it would very convenient to screw a McMaster needle right into the extra 1/8" air port. My coolant flow adjustment will be right there with the shutoff. Everything I need to tune except main line pressure will be within 6" of of the tool bit. As a matter of fact the Noga has a rudimentary main line control on the shutoff valve so I'll even have some limited control of that.

It's a bit pricey but McMaster has a precision 20 turn valve that comes in 32nd to 1/8 orifices. I'm thinking the 1/8" orifice because I'll be able to equalize the available line pressure between the two sides at the top flow end. With 20 turns in the middle even I oughta be able to find what I want.

So whaddayu guys think? Wrong tree?

SP

lazlo
11-11-2007, 11:30 AM
After some dedicated phone work I located a Noga air line from Wholesale Tool for $11.

Hi SP,

Is that the armored air line that Noga uses on their coolant systems? If so, that's a great price! What's the WTool part number?

Thanks,

Robert

pntrbl
11-11-2007, 11:42 AM
Yeah, it's the armored SS covered Noga line. Not sure of the WTool P/N but I gave 'em the Noga P/N, MC0380, and it came back 1M air line.

It did take a bit of phone time to find. My 1st call was ENCO where I bought it. Their response was since it's under a hundred bucks you should just buy another one! Someone else said January. I heard, "It depends on Israel" a couple of times. By the time the guy at WTool said, "sure", I was willing to pay whatever they wanted .....

SP

Paul Alciatore
11-11-2007, 12:42 PM
If I understand what you are doing correctly, I may see one possible problem. You are going to have a line from the air tank to the mister and it will have both cutoff and needle valve at the air tank end. I know something about air systems but am not completely familiar with the operation of misters. Would think they would either pressurize the coolant tank or use a venturi to draw coolant from the tank into the air stream.

In either case, you will have some air volume in the air line and possibly in the coolant tank. This air volume will act as a buffer downstream of your needle valve and could make adjustment difficult. You would not see an immediate change when you adjust it and would be tempted to make larger changes. Then, when the entire volume of air has had time to adjust to the new setting, you may find you need to adjust again in the opposite direction. If you need to make frequent adjustments this could be a real PITA. I would try to locate the needle valve as close to the point of use as possible.

pntrbl
11-11-2007, 01:59 PM
You may have a point there Paul. Air can compress. The tank can expand. Might be like a big spring every time I adjust it! The needle normally goes in the coolant line and since liquids don't compress you'd get direct action that way.

Back to the drawing board .....

SP