3/2 pneumatic valve help

[Liftoff]

Dan the decal is misleading, but that valve should operate as follows, port (P) the one opposite to the diagram decal is the pressure side (from buffer tank). Port (A) is the user, and should be connected to the ram. Port (R) is the return, ie its the exhaust from the ram and should not be connected to anything. In the normal position, port P is closed. Port A and R are connected (air in the ram is exhausted through port R)
When solenoid is energised, Port P is connected to port A, air from buffer tank flows to the ram. Port R is closed.

[Danjr1]

To be honest, these valves look so awful in terms of flow that I'm thinking that I might end up having to use larger 2 way 2 position valves with 4mm orifices (one normally open as the exhaust, the other normally closed as the inlet) but that would mean drilling a hole in the side of the ram and having a home made adapter welded on.

[Liftoff]

The only useful advice I can give you for better flow is a 5/2 valve+QEV+buffer setup. With this setup the size of the solenoid valve becomes irrelevant...what will matter will be the sizes of the ram orifice, the QEV and connections to the buffer.

[Danjr1]

to be honest, I'm getting fed up with trying to find pneumatic parts to fit into the design of bot i wanted to i might as well go to a drum spinner with interchangeable weaponry! will be much much easier!

[Danjr1]

obviously using a small 1mm diameter hole in the bottom of the ram in the same way as a full pressure system would work on a low pressure but what i was wondering was how much of a detrimental effect it would when firing?

[Liftoff]

I'd say the effect will be negligible, compare the areas of the inlet to the exhaust holes, the larger the difference the better

[Danjr1]

Cheers dude. I could maybe go for a 0.5mm hole maybe?

What do people reckon the flow rate in litres per minute would be on the valve below? Im not too sure whether id believe 12000 litres per minute as in their graph!

http://www.ebay.co.uk/itm/New-3-8-El...item1c1a8c45f1

[Bacon Wizard]

Check out this.

It's a gamble, but if the price can easily be beaten, it's one I would take. I didn't realise you were only dealing with 10bar.. many solenoids are rated at this because of what the coil will handle under pressure, not the rest of the valve. Well you can overvolt a coil just the same as for motors...and the vast majority are rated up to 8bar anyhow.

If you go for this and find one you want, you could re-list them either individually or with a better listing than this one anyhow.

http://www.ebay.co.uk/itm/Pneumatic-...item4d0c918520

I'm actually tempted miself, but I have a couple of festo banks already so I'd happily get out of your way. Let me know, so we don't end up in a bidding war.

[Danjr1]

Cheers dude but I won't be bidding on them. Beginning to learn that pneumatics aren't my thing

[Liftoff]

I didn't realise you were only dealing with 10bar.. many solenoids are rated at this because of what the coil will handle under pressure, not the rest of the valve. Well you can overvolt a coil just the same as for motors...and the vast majority are rated up to 8bar anyhow.

True, even without overvolting the solenoid and increasing the pressure, the valve will work...most 5/2 valves are pilot operated, so the solenoid just opens a small orifice and the valve spool moves pneumatically. ...but there is so much pressure you can increase on an 8bar rated valve. At above 11 bar air will start leaking at the valve heads.