3/2 valve as main valve?

bookyle · Wed Feb 08, 2012 8:33 am

Hi guys, just a quick question. Can I used a 3/2 valve as the main valve for an airsoft gun? So instead of using a 3/2 valve as a pilot valve, the 3/2 valve is connected to the supply and chamber, and the exhaust port connected to the barrel

thanks

wyz2285 · Wed Feb 08, 2012 9:03 am

yes you can, but what´t the size of the orifice? normally they are small, so it´s kind low flow to fire anything with normal compressor pressure (10bar), but if you go HPA, these valves I found in ebay doesn´t deal with more than 10bar.

bookyle · Wed Feb 08, 2012 12:03 pm

I'm thinking 1/4" threads, which is a bit bigger than 6mm

Planning to use regulated paintball CO2 as power source

wyz2285 · Wed Feb 08, 2012 12:14 pm

1/4 3-ways has about 3mm orifice max I think...

POLAND_SPUD · Wed Feb 08, 2012 6:45 pm

1/4 3-ways has about 3mm orifice max I think

yours is a direct acting one - so the solenoid has to retract the plunger to switch the valve

but there are also indirect acting valves that essentially have a small inbuilt valve just like yours but that valve is merely used to pilot the spool

Essentially it works like this>>>

don't worry it's fairly easy to identify one
Indirect acting valves look like these:

Direct acting valves look like this one:

Even a 1/8" indirect acting valve would be enough for an airsoft gun but 1/4" would give more power

bookyle · Wed Feb 08, 2012 7:07 pm

hmm, if that's the case, I might have to go back to QEV + pilot.

Do you know what's the max orifice for 3/8" 3-way or 1/4" QEV?

Edit is it just me or that 3/2 manual operated valves are hard to find? Most of what I found are solenoid valves

bookyle · Wed Feb 08, 2012 7:15 pm

so would this be an indirect acting one?

http://www.ebay.com/itm/3-Way-2-Positio ... 2c57608586

what about manually activated ones?

http://www.ebay.com/itm/3-2-Way-Pneumat ... 2c5ce416c0

bookyle · Wed Feb 08, 2012 7:33 pm

here is what I'm trying to do

the chamber is filled from the air supply, when the 3-way valve is opened, air supply is closed off, and the chamber volume is dumped into the barrel

Would something like this

http://www.clippard.com/store/display_d ... sku=FTV-3P#

or this

http://www.ebay.com/itm/3-2-Way-Pneumat ... 4-NPT-Dete nted-/190537012928?pt=LH_DefaultDomain_0&hash=item2c5ce416c0

allow the chamber volume to be dumped quickly?

POLAND_SPUD · Wed Feb 08, 2012 8:12 pm

so would this be an indirect acting one?

Yes. But as far as I can tell it looks like a cheapo chinease valve... one that's seriously overpriced I mean... also try to find a normally open valve

here is what I'm trying to do

yeah it will work

what about manually activated ones

there are indirect acting manual valves but the one you posted is not

Indirect valves have a little triangle shape right next to the actuator
(can be seen on page 46 of this book http://www.digital-circuitry.com/DOC/EL ... 0Basic.pdf)

bookyle · Thu Feb 09, 2012 6:12 pm

Thanks a lot poland spud

I think I'm going to buy this valve

http://store.norgren.com/us/en/detail/v ... ool-valves

Currently trying to find a cheaper source, Norgren has a $50 minimum order policy...

POLAND_SPUD · Thu Feb 09, 2012 8:37 pm

Currently trying to find a cheaper source

there are tons of these on ebay - I've never bought one but it's a 3way normally open valve - and that's exactly what you are looking for

http://www.ebay.com/itm/3V210-08-DC-24V ... 5ae4a848c0

bookyle · Thu Feb 09, 2012 10:16 pm

hmm, maybe I should consider solenoid valves, they do seem to simplify the trigger placement somewhat.

One more question, does it have to be normally open? Can't the chamber be filled from the exhaust port, and the normal supply port is used as the exhaust?

POLAND_SPUD · Fri Feb 10, 2012 7:37 am

Can't the chamber be filled from the exhaust port, and the normal supply port is used as the exhaust

only if it was a universal valve - but most indirect acting solenoid valves are not universal - they are either NO or NC

If you're wondering why then have a look at this pic again

See that tiny passage from the P (marked as 'in' in the pic) to the solenoid itself ??
if you connect your air source to a different port it won't work - indirect acting valves need pressure to operate

bookyle · Fri Feb 10, 2012 11:16 am

Oh, now I see. The valve you posted has 5 ports, I was thinking about 3 port 3 way valves.

For the valve that you posted, the chamber would be attached to the port between "In" and "Idle output", and the barrel attached to the right most port, right?

oh, and can I block off the other two unused port with a plug?

POLAND_SPUD · Fri Feb 10, 2012 11:43 am

The valve you posted has 5 ports, I was thinking about 3 port 3 way valves

3 way indirect acting valves work in the same way

For the valve that you posted, the chamber would be attached to the port between "In" and "Idle output", and the barrel attached to the right most port, right?

yes, that's exactly how it would work