Directional Control Valves (3way valves and stuff like that)

Lockednloaded · Sat May 22, 2010 1:57 pm

i'm buying a 1/4" 3-way valve, and I have two options: a manual push button one ore an air actuated one. they both cost about the same amount of money, but which one will have more flow

Gun Freak · Sat May 22, 2010 2:10 pm

I would do the push button one, so you won't have to buy a pilot for the other one... unless it comes with one... but it seems if the one needs a pilot then it will have some sort of QEV design which would mean more flow and better opening time, which is better piloting a QEV.

Lockednloaded · Sat May 22, 2010 2:13 pm

well it has a 1/4" port that i could put a blow gun into, i have the parts
and the manual one has an awkward looking button trigger
push button
air piloted

Gun Freak · Sat May 22, 2010 2:33 pm

In that case, do the blowgun piloted, trigger feel, and most likely better flow. By the way, I was looking at the same exact push button valve there.

Edit, the air piloted has 11.20 USD shipping, push button is free shipping, gonna save 5 bucks with the push button, mate.

POLAND_SPUD · Sat May 22, 2010 2:52 pm

both of them have more less the same flow... If I were you I'd buy the one with a push button...

EDIT
lol I missed that earlier but it says that both of them have 0.89 Cv flow rate
so yeah they flow is the same

Gun Freak · Sat May 22, 2010 3:21 pm

Yeah so you'd be way better off with the push button. You can always make a little lever trigger for it if you want the feel, but you're gonna save the shipping costs with the push button.

Lockednloaded · Sat May 22, 2010 4:57 pm

ok i just bought my 3/4" QEV for a main valve, will that push button be able to pilot it?

Gun Freak · Sat May 22, 2010 5:01 pm

Oh yes. Can't wait to see your semi auto! Where are you getting your cylinder from? Maybe a semi can be my summer project.

Lockednloaded · Sat May 22, 2010 5:05 pm

I'm using a bamba single acting cylinder, 1.5" stroke. I'm going to house it inside an airtight compartment inside the back of the loading mech so I do no have any problems with mechanical seals.
I'm deciding what projectile to use, paintballs, marbles, or even a special dart mag/ NERF mag for the upcoming competition.

PVC Arsenal 17 · Sat Jul 10, 2010 2:23 pm

I just thought I would post this video showing a sleeve valve (slide check) operating a QEV + cylinder.

The only major difference between a sleeve valve and a true 3-way valve is that it lacks spring return. A spring can be added to a sleeve valve quite easily, and from either side of the sleeve. This means it can be used a Normally Open or Normally Closed Valve. The lack of spring return, however, can be quite useful.

If you're looking to build a gun which uses cylinders and you want to have full control over both strokes of the cylinder, a sleeve valve will do just that. For example, I'm building an assisted bolt action Nerf gun. The bolt is actuated by a cylinder instead of manually. When the trigger (valve) is in the forward position (ready to fire) the breech is closed. When the trigger is pulled, the gun fires and the breech opens. Due to the lack of spring return, the breech stays open, allowing me to load a new round. I then manually reset the trigger (much easier than cycling a bolt manually) and the breech closes as the gun fills.

Sleeve valves are often easier to find than true 3-way valves because they're used in paintball in remote lines (referred to as slide check valves).

For anyone using DCV's to pilot quick exhaust valves: Sometimes the most ergonomic configuration of your pneumatic circuit leads to lots of pilot volume and a loss of performance due to the time required for your DCV to vent it. In this case, it may help to add another quick exhaust to your circuit to help pilot your primary valve. In the interest of conserving space and costs, you can buy an inline quick exhaust to do the job. I've had great success with the Pneumadyne C570501.

Keep in mind these inline valves vent to the atmosphere via multiple nonthreaded exhaust ports, so the air is wasted. Consider a small, conventional QEV such as one from Clippard's JEV line if you want to make use of that air somehow as they have threaded exhaust ports. If you still need to conserve space and want to use that air as well, look into an inline valve from Clippard's JLEV line which also have threaded exhaust ports.

I have nothing but good things to say about Clippard's JEV line of QEVs. They work great even as primary valves for firing low-mass projectiles. I'm sure the same quality can be expected from the JLEV line.

Info on both lines of Clippard's J-Series QEVs

budabob07 · Sat Nov 13, 2010 9:36 pm

would this be a suitable valve to pilot a QEV
http://cgi.ebay.com/1-New-Humphrey-TAC2 ... 1c170d41f0

POLAND_SPUD · Sat Nov 13, 2010 9:56 pm

yeah, it seems ok. Sure it would be better if it was rated to let say 15bar but it can probably handle 20 bar

budabob07 · Sat Nov 13, 2010 9:59 pm

thanks. also, i probably wont need it anywhere near 20 bar, as i am not planning on making a high pressure system (plus, my air compressor goes up to 125 only

POLAND_SPUD · Sat Nov 13, 2010 10:04 pm

yeah, that's what I expected... anyway there are lots of cool uses for these things - things that don't require high pressures

did you know you can build a push button metering system for a hybrid/combustion? Of course you can use a BV just like most ppl but a push button system seems a lot cooler IMO

@MC
you've got a hybrid and some DCVs, right?

nature-boy · Wed Mar 09, 2011 4:40 pm

I got a (IMO very cool) 3/2 solenoid from ebay for very cheap, and although I already did some researches and reading, I still got a few questions.

As you can see in the diagram on it, it is a indirect acting, normally open valve, with 3/8 female ports, rated to 10bar and 2500 l/min flow-rate.
(more is here: http://www.kiowa.co.uk/EF163164 ...of course there is also a original data-sheet on the festo-page, but somehow their homepage doesn't really work for me today...)

My questions:
- How much above 10bar can I go safely, without destroying the valve?

-the printing on the solenoid itself says 24V DC 1,5W (and so does the data sheet say)
...BUT: printed on the adapter is a diagram of the circuit build in to it,
which is a bit confusing:
I recognize a LED (which is located on the top of the adapter),
2 (or 3??) diodes, one ground-line and other lines (sw1 and sw2),
a resistor, aaand: 48VAC/DC , 4A written above the diagram.
So... is the adapter a inbuilt rectifier? Do I have to run the whole unit
with 48V ? Can I use the solenoid without the adapter with 12V DC?
Because I would like to run it on batteries.
And which wire is which? (sw1/2???) One is green-yellow (ground) and
the two other ones are black.
other ones are both black...

-what is the M5 threaded port 10/12 for? data-sheet says: pilot air port...
can I just ignore it??? because somewhere I read the actuating-pilot-pressure is "internal".... A yes I don't think that it is the exhaust port for the pilot, this seems to be another one above this one (also M5).

I know a lot of questions... ah yes did I mention that I got it for 2,10€ ?

(+2,20€ shipping), the regular prize is about 100€...