This valve assy was fitted to my router. what's it supposed to do?

[Richard]

I'm trying to work out exactly what the purpose of this valve assembly is.

It was attached to the body of a spindle on a gantry cnc router.

Clearly it is supposed to direct either air or coolant to the cutter, BUT, it has two pipe connections, one with a valve (actually it's a Meter-in speed controller valve) and one without.

The pipe connector on the right of the block, without the valve, has a pipe running back to a electricly operated valve which has another length of pipe from it which is just floating about free.

Obviously I can connect the electric solenoid valve to compressed air and have an air jet blowing onto the cutter, but whats the purpose of the valve on the cutter end?

I wondered if it would allow coolant to be drawn up via another pipe to give a mist?

I'm not sure the meter-in speed controller valve is meant to have liquid in it.

I can just bin this assembly and run a flood coolant with a small submersible pump instead. It might be useful to keep as an air blast for use on wood, mdf etc?

[m_c]

It's a venturi setup for mist coolant. The metered inlet would connect to a container of suitable coolant.

[Richard]

It's a venturi setup for mist coolant. The metered inlet would connect to a container of suitable coolant.

So does the coolant feed have to be pressurised? (I had hoped not, but....)

[m_c]

So does the coolant feed have to be pressurised? (I had hoped not, but....)

It depends on how it's been designed. If it is a venturi, then it should create a vacuum and draw fluid out an unpressurised container.
However it's maybe not a venturi, in which case it does need the fluid to be pressurised.

Only way to find out, is connect it to a suitably regulated air supply, and see if it sucks or not.

[Richard]

It depends on how it's been designed. If it is a venturi, then it should create a vacuum and draw fluid out an unpressurised container.
However it's maybe not a venturi, in which case it does need the fluid to be pressurised.

Only way to find out, is connect it to a suitably regulated air supply, and see if it sucks or not.

See if it sucks or suck it and see? LOL!

I did initially try connecting a pipe to the valve (top of pic) with the end in some coolant but it just blew bubbles!

There doesn't seem to be any venturi effect....

[cropwell]

The top one is probably the air inlet as it has a valve on it.

[m_c]

See if it sucks or suck it and see? LOL!

I did initially try connecting a pipe to the valve (top of pic) with the end in some coolant but it just blew bubbles!

There doesn't seem to be any venturi effect....

What pressure did you use?
If it is a venturi, and you used too high a pressure, the restriction of the outlet would cause it to blow air out the coolant inlet, instead of creating a vacuum.
Most of these things are designed to run around 1-3bar, so start with a pressure regulator fully wound off, then gradually increase the pressure.