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3/2 valve as main valve?
Posted: Wed Feb 08, 2012 8:33 am
by bookyle
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
Posted: Wed Feb 08, 2012 9:03 am
by wyz2285
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.
Posted: Wed Feb 08, 2012 12:03 pm
by bookyle
I'm thinking 1/4" threads, which is a bit bigger than 6mm
Planning to use regulated paintball CO2 as power source
Posted: Wed Feb 08, 2012 12:14 pm
by wyz2285
1/4 3-ways has about 3mm orifice max I think...
Posted: Wed Feb 08, 2012 6:45 pm
by POLAND_SPUD
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
Posted: Wed Feb 08, 2012 7:07 pm
by bookyle
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
Posted: Wed Feb 08, 2012 7:15 pm
by bookyle
Posted: Wed Feb 08, 2012 7:33 pm
by bookyle
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?
Posted: Wed Feb 08, 2012 8:12 pm
by POLAND_SPUD
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)
Posted: Thu Feb 09, 2012 6:12 pm
by bookyle
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...
Posted: Thu Feb 09, 2012 8:37 pm
by POLAND_SPUD
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
Posted: Thu Feb 09, 2012 10:16 pm
by bookyle
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?
Posted: Fri Feb 10, 2012 7:37 am
by POLAND_SPUD
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
Posted: Fri Feb 10, 2012 11:16 am
by bookyle
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?
Posted: Fri Feb 10, 2012 11:43 am
by POLAND_SPUD
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