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Ideas needed for a pop-open stay-open pressure relief valve.
Posted: Mon Jul 06, 2009 8:46 am
by boyntonstu
Imagine shooting a piston down a .5 sq in chamber/barrel with a 200 lb force at 140 fps..
(A fast bicycle pump))
At the bottom of its travel the air will be at 400 psi.
What I need is a valve to open and stay open when the 400 psi is reached.
The projectile will see the 400 psi when the valve opens and it will shoot out of the barrel.
One way is to place the relief valve in a "T" and the arrangement would be like this:
>==========T<spring> opens and stays open
......................=======================barrel
Any ideas?
Boyntonstu
Posted: Mon Jul 06, 2009 9:15 am
by twizi
why dont you try your ideas like the compreser a pump and all the other stuff u post instead of just posting ideas about it
ps are you really 70
Posted: Mon Jul 06, 2009 10:15 am
by boyntonstu
twizi wrote:why dont you try your ideas like the compreser a pump and all the other stuff u post instead of just posting ideas about it
ps are you really 70
I have 6 patents and numerous other inventions that were conceived by sharing my ideas with intelligent people and listening to their responses.
My methods worked well enough for me to retire at very young age.
This is me, how old do I look?
FYI and possible enjoyment:
See my $100 elevator video here:
And:
Larry David beats his smoke detector to death with a bat
BoyntonStu
In the government, you measure with a micrometer, mark it with chalk, and cut it with an axe!
Posted: Mon Jul 06, 2009 11:55 am
by twizi
it was not in insult sorry if you thought it was
i would just think a 70 yearold would be in spuding and spudguns
sorry

Re: Ideas needed for a pop-open stay-open pressure relief va
Posted: Mon Jul 06, 2009 11:59 am
by Technician1002
boyntonstu wrote:Imagine shooting a piston down a .5 sq in chamber/barrel with a 200 lb force at 140 fps..
(A fast bicycle pump))
At the bottom of its travel the air will be at 400 psi.
What I need is a valve to open and stay open when the 400 psi is reached.
The projectile will see the 400 psi when the valve opens and it will shoot out of the barrel.
One way is to place the relief valve in a "T" and the arrangement would be like this:
>==========T<spring> opens and stays open
......................=======================barrel
Any ideas?
Boyntonstu
If shooting steel BB's, retain them on a neodymium magnet. At the end of the piston stroke, the pressure can be just enough to unseat the BB. The BB is the valve.
Posted: Mon Jul 06, 2009 1:02 pm
by jackssmirkingrevenge
Ideas needed for a pop-open stay-open pressure relief valve.
I think you'll find they're called "burst disks"

Posted: Mon Jul 06, 2009 1:18 pm
by spudtyrrant
jackssmirkingrevenge wrote:I think you'll find they're called "burst disks"

didn't you conclude that even a piece of clear tape over a 6mm diameter wouldn't burst at 400psi until you slightly unscrewed the union and if he's planning on shooting .177 cal projectiles i don't think that is the way to go i would just go with the old ball detent o-ring combo

Posted: Mon Jul 06, 2009 1:19 pm
by boyntonstu
jackssmirkingrevenge wrote:Ideas needed for a pop-open stay-open pressure relief valve.
I think you'll find they're called "burst disks"

Yes, burst disks will do in many cases.
In this concept ideally the burst disk/valve needs to be in the same tube as the piston and the projectile.
BoyntonStu
Posted: Mon Jul 06, 2009 1:21 pm
by boyntonstu
spudtyrrant wrote:jackssmirkingrevenge wrote:I think you'll find they're called "burst disks"

didn't you conclude that even a piece of clear tape over a 6mm diameter wouldn't burst at 400psi until you slightly unscrewed the union and if he's planning on shooting .177 cal projectiles i don't think that is the way to go i would just go with the old ball detent o-ring combo

Good idea for a ball, but not ideal for a cylinder shaped projectile.
Thanks,
BoyntonStu
Posted: Mon Jul 06, 2009 6:18 pm
by jonnyboy
How about a snap valve with a spring catch. I can think of a couple possible designs. One really stands out in my mind. Although you'll have to unsnap it to fire again. Diagram to come
Posted: Mon Jul 06, 2009 7:39 pm
by Moonbogg
Try playing with spring plungers.