Valve to replace burst disk
Posted: Sat Nov 10, 2012 2:27 am
Has anyone ever come upon any inline pressure release valves that could replace a burst disk?
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Re: Valve to replace burst disk
Posted: Sat Nov 10, 2012 3:32 am
Posted: Sat Nov 10, 2012 8:47 pm
Very interesting. Did you just come across that in a museum or planned on seeing it?
Posted: Sun Nov 11, 2012 12:40 am
I was planning on going to the museum but didn't know those were there, pleasant surprise indeed 
Posted: Sun Nov 11, 2012 4:54 am
What about Tech's Quick dump valve
Posted: Sun Nov 11, 2012 5:06 am
Which thread is that?
Posted: Mon Nov 12, 2012 4:02 am
Posted: Mon Nov 12, 2012 5:48 am
Yeah that's similar to mine so far but I've had concerns about using the piston in a high mix hybrid simply because it's going to act like a projectile against the rear every time I fire. Not sure how long it would hold up for
Posted: Mon Nov 12, 2012 5:53 am
What projectiles were you planning on using? An o-ring detent might be ideal for you.
If this is for a hybrid, the QDV wouldn't work anyway because it is a balanced valve, which is not being held shut by a pressure imbalance.
If this is for a hybrid, the QDV wouldn't work anyway because it is a balanced valve, which is not being held shut by a pressure imbalance.
Posted: Mon Nov 12, 2012 7:05 pm
a normal QDV wouldn't work but who said it has to be balanced ?
Posted: Mon Nov 12, 2012 10:41 pm
I haven't been on here in a while - but I'm glad I caught this post! This is sort of the same idea that the Invert Mini paintball gun operates on (a soft start of the piston which then cascades into faster motion)POLAND_SPUD wrote:a normal QDV wouldn't work but who said it has to be balanced ?
I had other ides for valveless methods but this is a pretty good idea for a valveless hybrid!
Can't wait to graduate... I really want to get back to working on these time wasters and hash out my ideas lol.
Posted: Tue Nov 13, 2012 2:53 am
Technically it's not valveless though. Semantics, I knowmobile chernobyl wrote:I had other ides for valveless methods but this is a pretty good idea for a valveless hybrid!
but I would consider a launcher "valveless" when the projectile itself is restraining the pressure, and pops out like a champagne cork when either a restraint is removed, or chamber pressure increased.Posted: Tue Nov 13, 2012 8:31 am
I can agree it may not be valveless in it's static position - but it certainly will be after each shot! 
Posted: Wed Nov 14, 2012 6:12 am
Yeah both of those ideas should work in most setups. The second one does seem quite complex though, is that of a paintball marker?
The only thing is I'm hoping to come across a sort of valve or overall design that is simple where it's parts have less potential for wear in high mixes and rates of fire. Which is why I have moved away from sliding o-rings and too many moving parts. I've also had to keep in mind flow restrictions which is why I'd be looking at some kind of valve or seal that opens directly into the barrel.
The sketch below is one idea I had a while ago, but if I was going to make one with a piston now I would have a similar kind of setup but with a much smaller piston in a separate cylinder, ontop of the chamber at the front, which is connected to a type of ball valve on the barrel opening. So in theory, once the pressure rises in the chamber, the piston will be forced forward, venting the rear of the cylinder allowing the piston to move the full stroke. Attached to this piston would be a conrod fitted to the valve handle.
So in comparison to the original design, this would be to try and reduce the forces on the piston and rear of the chamber, while allowing for an unrestricted flow. (perhaps I should draw up another sketch)
But if I could just find a valve that acted like a burst disk I wouldn't have to mess with all of it!
jackssmirkingrevenge - I have't really thought about projectiles at this stage, just trying to get a good working design down pat first.
The only thing is I'm hoping to come across a sort of valve or overall design that is simple where it's parts have less potential for wear in high mixes and rates of fire. Which is why I have moved away from sliding o-rings and too many moving parts. I've also had to keep in mind flow restrictions which is why I'd be looking at some kind of valve or seal that opens directly into the barrel.
The sketch below is one idea I had a while ago, but if I was going to make one with a piston now I would have a similar kind of setup but with a much smaller piston in a separate cylinder, ontop of the chamber at the front, which is connected to a type of ball valve on the barrel opening. So in theory, once the pressure rises in the chamber, the piston will be forced forward, venting the rear of the cylinder allowing the piston to move the full stroke. Attached to this piston would be a conrod fitted to the valve handle.
So in comparison to the original design, this would be to try and reduce the forces on the piston and rear of the chamber, while allowing for an unrestricted flow. (perhaps I should draw up another sketch)
But if I could just find a valve that acted like a burst disk I wouldn't have to mess with all of it!
jackssmirkingrevenge - I have't really thought about projectiles at this stage, just trying to get a good working design down pat first.