Need a valve to select air or coolant

We had some injuries at work with operators getting chips in their eye(s) from blowing off parts. Management wants to get rid of blow guns and the operators want to get
rid of the goggles they have to wear atm.
On one machine that runs dry as in no coolant, I plumbed in an air valve tied to the coolant pump contactor that is disabled to do an air blown on the part that is being machined. That is working out fine.
On the other machines, we need to run coolant. I'm going to need to use the coolant system plumbing for both coolant and air. I need a valve that will electrically switch between two sources. Preferally a single input valve with a default position. Any ideas?
Then there is that other bother, my machines tend to be 199x stuff. Mostly Mori's, were there typically spare outputs tied to M codes or am I SOOL?
Thanks,
Wes
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snipped-for-privacy@lycos.com wrote in

How about one of these - http://img.directindustry.com/images_di/photo - g/blow-off-fan-for-machine-tool-413855.jpg
It's a folding fan that you tool change into the spindle. When you run the spindle up the blades unfold, then you move it around to blow off the work and table.
--

Dan

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On 3/20/2010 10:04 PM, snipped-for-privacy@lycos.com wrote:

Sounds like you need smarter button pushers.. ya know, the ones that wear safety glasses, or keep their head behind one of the doors while blowing the parts off.
As for the electrical switching, donno.. sorry :/
Good luck ;)
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snipped-for-privacy@lycos.com wrote:

What you're asking for is a three way valve, and there are unlimited choices. Pick one that'll handle the air pressure, since that's highest, and it'll run coolant too. Go big on the fitting and orifice sizes, though, so the coolant doesn't just trickle.
I've done the same thing another way, though. We have machines that run either chilled air or coolant, depending on the job. I've plumbed both air and coolant to the point where flow enters the back of a lathe turret, or the top of a VMC spindle, or the tail end of a lathe sub-spindle. Leaving the rotary unions in place, if they exist, I just install a tee with air in one side and coolant in the other. Between the supplies and the tee, I use cheap, simple check valves, so the two flows can't find their way into each other's tubes. Use existing M codes to run coolant. A simple on/off solenoid valve and any spare M code pair can turn the air on and off.
Or, use a manual toggle switch to re-route the machine's relay output so the same M code can run either air or coolant, depending on the switch position. The only caveat with that trick is that the switch will also need to disable the coolant pumps when you select for air. You don't want them running dead-headed for long periods. Disabling the pumps usually just means running the existing wire that goes from a relay output to the pump's mag contactor, and having the (DPDT) switch close that connection only when you want coolant.
HTH! KG
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