well I've really been trying come up with a good design for quite a long time... I've seen dozens of pics of valves used on paintball guns and similar stuff...
a couple of days ago I drew this 'postive pressure (actuated/piloted) valve' and I though 'ohh this could work and seems to be pretty simple'
then I looked at it again and I realized that it looks exactly like an air piloted 3 way valve (meaning those off the shelf DCV valves that I talk about all the time, 24/day 7 days a week... you know that stuff that you normally skip when you see I mention it again
this really is just a scaled up version of them...
possibly it isn't even necessary to machine the valve as there are off the shelf DCV in larger sizes (3/8", 1/2")...
you'd just have to make sure that it is:
-an air operated direct acting spool valve (as indirect/assisted valves often don't handle high pressures well;similarly poppet valves are no good as they are not balanced)
-that its housing is thick....
-check if the spool is made of metal or not
-is normally open or bidirectional valve (depending on which port you choose it can be both NO and NC valve)
well yeah I know that hammer valves are not that bad... if you think of it there isn't really that much difference between the hammer valve, the piston valve and the QDV
but I find the QEV + DCV + air cylinder combo to be the simplest and most reliable way to achieve semi auto and full automatic operation of the gun... so I am looking for a design that would allow me to utilize this system at HPA pressures
just think of all those pb guns that rely on exactly the same principle of operation