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Posted: Thu May 01, 2008 6:26 pm
by MrCrowley
DYI wrote:
Mechanically speaking, I just can't see a ball valve being faster then a blow gun on a sprinkler valve. Honestly.
It is when it's opened by a high explosive driven ram...
What about an 8000psi piston valve made from titanium or magnesium with a large sealing face but tiny seat?

Surely that's quicker then a ball valve opened by a high explosive driven ram...


Just noticed you said high explosive, that's well over 8000psi in pressure generated...

Posted: Thu May 01, 2008 6:27 pm
by elitesniper
Then might as well use the explosive its self :shock: , but seriously don't :)

Posted: Thu May 01, 2008 6:31 pm
by bigbob12345
Using explosives to open a valve is an interesting idea.

Maybe you could open a 1/4in ball valve using a firecracker that you would slip in a ram every shot.
Just make a little ram that fits a fircracker well. Stick a cracker in and close it off, and then ignite the fuse by some electric way such as a bbq ignitor.

I might actually try that

Posted: Thu May 01, 2008 6:33 pm
by SpudFarm
that made zero sence bigbog..

Posted: Thu May 01, 2008 6:34 pm
by bigbob12345
I just realized
Ill go reword it
Sorry :lol:

Posted: Thu May 01, 2008 6:43 pm
by DYI
Just make sure you don't use air in the magnesium piston valve, the valve itself might auto ignite at 8000 psi :lol:

The explosive driven ram was never intended to be a practical idea as far as I know, it was just to show that it could be done. And seriously, making pressure vessels to contain solid explosive detonations isn't child's play.

Just FYI, trying any of the following is blatantly illegal in almost any country. This'll probably get deleted by a mod, and I shouldn't be wasting my time typing it, but here goes: Yea, your rite. It got deleted.


Don't try this at home kids. Your family might miss you. :roll:

Posted: Thu May 01, 2008 6:55 pm
by jrrdw
You guys know disscusion of explosives is not allowed.

Posted: Thu May 01, 2008 7:09 pm
by DYI
Good job jrrdw, that took less than 10 minutes. You're really on your toes here. :lol: Ah well, typing it all out helps my thought processes anyway.

Posted: Thu May 01, 2008 7:11 pm
by bigbob12345
Aww didn't get to read what DYI wrote before it got deleted :(
Mind if you pm it to me DYI
Whatever it is Ill most likely never try it, Im just curious

Posted: Thu May 01, 2008 7:14 pm
by Ragnarok
MrCrowley wrote:What about an 8000psi piston valve made from titanium or magnesium with a large sealing face but tiny seat?
Actually, in contrary to what most believe, a piston valve will actuate faster with a larger seat, as the pressure in the pilot needs to fall lower for the piston to start to move, and therefore once the full front face of the piston is exposed, the piston will have a greater net force on it - which of course results in faster opening.

That's the reason HEAL's piston was modified to have the largest practically possible seat and sealing face (22.1mm, compared to the barrel's 20.3mm ID).
Not only does it give more flow, but it opens faster. It's been nearly a year since I first made HEAL, and in spite of a new in-flux of other high pressure cannons, it's valve has still got that significant advantage.

I sometimes wonder what the results of the piston design will be on the cannon to be known as 3vo - think HEAL, but built to be even more efficent, run at 500 psi, and semi-automatic to about 120 rpm.
Just the system to supply two full 35 bar fills a second is going to be a heck of lot of work.

Posted: Thu May 01, 2008 7:36 pm
by jrrdw
DYI wrote:Good job jrrdw , that took less than 10 minutes. You're really on your toes here. :lol: Ah well, typing it all out helps my thought processes anyway.
Any more discussion of prohibited discussion will lead to this thread getting locked, and thanks I do what I can.

Posted: Thu May 01, 2008 7:48 pm
by Velocity
DYI wrote:Just make sure you don't use air in the magnesium piston valve, the valve itself might auto ignite at 8000 psi :lol:
That would be the coolest thing in spudding history...the projectile should be magnesium too :P

Posted: Thu May 01, 2008 7:57 pm
by MrCrowley
Ragnarok wrote:
MrCrowley wrote:What about an 8000psi piston valve made from titanium or magnesium with a large sealing face but tiny seat?
Actually, in contrary to what most believe, a piston valve will actuate faster with a larger seat, as the pressure in the pilot needs to fall lower for the piston to start to move, and therefore once the full front face of the piston is exposed, the piston will have a greater net force on it - which of course results in faster opening.

That's the reason HEAL's piston was modified to have the largest practically possible seat and sealing face (22.1mm, compared to the barrel's 20.3mm ID).
Not only does it give more flow, but it opens faster. It's been nearly a year since I first made HEAL, and in spite of a new in-flux of other high pressure cannons, it's valve has still got that significant advantage.

I sometimes wonder what the results of the piston design will be on the cannon to be known as 3vo - think HEAL, but built to be even more efficent, run at 500 psi, and semi-automatic to about 120 rpm.
Just the system to supply two full 35 bar fills a second is going to be a heck of lot of work.
Good news for me, i'm making a BB coaxial in a 15mm galv pipe and I had to sleeve the pipe with copper to counter the galv seam, so I made a piston out of two 9mm shell casings and it's only marginally larger then the seat.

Posted: Thu May 01, 2008 9:32 pm
by DYI
Any more discussion of prohibited discussion
Unless there's a problem with discussing the discussion of prohibited discussion, I'd like to say I'm confused :lol:

Posted: Thu May 01, 2008 11:08 pm
by OuchProgramme
Wait...why don't you just have a pneumatic ram which hits the ball valve?
Have some acceleration time(extra long barrel)

It'll look really strange, but whateva