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Hybrid Valve design

Posted: Thu Jul 08, 2010 7:52 pm
by BigBang J
What do you guys think of this?

It is basically a pop valve, the opening pressure depends on the strenght of the spring used, so it can be tweeked there.
The front valve piston will be made from a flouropolymer material like PTFE for smooth opperation and a good seal.
The seal will not be made from the cylinder wall to the OD of the piston, but rather the front of the piston will be conical and fit into a hole
creating the seal. This seals the pressureized gas/air mix in the combustion chamber. When the gun fires the pressure will force the piston back, the secondary piston you see
in the rear will catch on the sear located on the bottom of the valve. This will ensure that all of the gas escapes. The front piston will slide back so that the ports on the side will be opened and the gas escapes
through the ports through some metal tubing and is guided to the coupling and barrel.


Also I am looking for some software for calculating helpful thing for building Hybrids, like chamber volume chamber to barrel ratio etc.

Posted: Thu Jul 08, 2010 8:21 pm
by jhalek90
This will not work.

Unless i am mistaken,the surface area difference of your "front piston" will actually cause it to remain shut.

I see no way that this will open.

Posted: Thu Jul 08, 2010 8:33 pm
by kjjohn
@jhalek90 - I believe you misinterpreted his design. There is no pressure between the two pistons at any time, so it would work. The cone shaped piston at the front is the only piston exposed to the chamber pressure, and upon ignition, it pushes back, uncovering the two openings in the side. The two pipes coming off the sides lead to the barrel, not the chamber. From what I understand, the only reason for the back piston is to catch on to the sear to keep the valve open.

So yes, I do believe this may work. However, it is very similar to every other hybrid valve design I have seen.

Posted: Thu Jul 08, 2010 9:38 pm
by inonickname
I'm actually going to agree with Jhalek. With the way the drawing is, I can't see it working. The forces seem balanced to me.

Posted: Thu Jul 08, 2010 10:08 pm
by ramses
If chamber pressure is applied to the extreme right port, it may work.

Posted: Fri Jul 09, 2010 10:45 am
by c11man
he made a popoff valve with a latch to keep it open, it will certainly work. but power will not be great because the valve has poor flow and not very fast opening time. the piston might might move too fast for the latch to catch it.

he designed it to have the chamber on the right hand port and the barrel on the right

Posted: Fri Jul 09, 2010 1:10 pm
by BigBang J
kjjohn has got the concept correctly.

Try to focus on the concept for now, like I said the proportions have not been worked out. And my barrel is only going to be 1/4" dia.

c11man "he designed it to have the chamber on the right hand port and the barrel on the right"

No the cumbustion chamber is on the right side and the barrel is on the left side of drawing. So the gas enters the right side of valve, and exits out of the side vents to barrel via metal tubing.

Why do you think it will have poor air flow? If it is because of the proportioning of the drawing then thats ok because the proportions are not accurate.

Abybody have a better idea for a high flow valve?

Posted: Fri Jul 09, 2010 1:13 pm
by Gun Freak
BigBang J wrote:Anybody have a better idea for a high flow valve?
A burst disk. The flow doesn't get much better.

Posted: Fri Jul 09, 2010 1:21 pm
by SpudBlaster15
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Posted: Fri Jul 09, 2010 1:25 pm
by c11man
i made a typo, i meant the barrel when on the left, but i typed right instead.

to get better flow a piston valve could do it.

Posted: Fri Jul 09, 2010 1:59 pm
by BigBang J
I did not want to use a burst disk if I could avoid it.

SpudBlaster15 Ahh. so the piston in your diagram seals directly to the rear of the barrel?

Posted: Fri Jul 09, 2010 2:11 pm
by saefroch
Yes, SpudBlaster posted a fairly run-of-the-mill barrel sealing hybrid piston valve. They are built and operate almost exactly like a pneumatic piston valve.

Posted: Fri Jul 09, 2010 2:34 pm
by SpudBlaster15
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