Enlarged mechanical high-presure "paintball" valve

[SEAR]

Hi. I want a valve, a mechanical one ideally, that could quickly release say 0,4L of 60bar (850 psi) to the atmosphere. I need the high pressure for loudness and compactness. The pressure applied to such a valve could be even in tens of kilograms (it doesn't have to be opened by a finger push The orifice should be better than in the mechanical paintball valves (the input there is usually 1/8"). Any ideas what may I use? QEVs are usually only for 10 bar and require some pilot valve.

[flyweightnate]

That's a lot of pressure for a quick- acting valve.

Anything over 30 psi will still create choked (i.e. "speed of sound") flow, and therefore a sonic boom upon diffusion, and be much safer, and easier to find a valve for. That volume is also a ton of energy. Somewhere on the order of 250 paintballs worth at 300fps.

I'm pretty well- versed in the industry, but can't thing of anything to fit the bill. I'd ask some oil and gas guys, who will think you're crazy.

[imped4now]

Woof. Good stuff. What's the projectile?

[SEAR]

Not exactly a projectile. I decided to take a metal WWII AT mine and make it go boom acoustically and with a marking powder visually when a vehicle goes over it. That's why the volume of air and higher pressure I just want the effect to be visible and audible. I know the "standard" paintball mines and they are so so. Good enough as AP mine but AT mine should be more "pronounced". One-way valve could be a possible solution. There are several games with the real armored vehicles where I play.

[Alexndl]

You could use a piston activating a poppet valve. If you use a fix volume dump chamber before the valve you dont have to worry about dwell. It would be one valve to fill the dump chamber and seal it and a piston to open the poppet valve to release the shot

[Spider!]

Have you looked at the metadyne havoc valve? It's an unbalanced internal piston (spool) that wants to vent at operating pressure but is pilot balanced. You can make one that is mechanically restrained before charging, then tripped to vent.

The spool passes through the front and back of the dump chamber and has a smaller front vent opening than the rear seal. The imbalance in size of those ports determines the force that pulls the spool open and overcomes the seal friction. A trip mechanism holds the spool in place at the rear where it extends outside of the dump chamber.

I had a paintball version in a pirate pistol on the last MCB.

[flyweightnate]

Sounds fun!
Be careful with the energy. That amount of air would expand (at the speed of sound) to occupy 20 L of space. It could blow off a track or send something airborne.

I'd consider having some kind of resonator chamber for the noise, but slowly bleeding all that air from the chamber through to the powder launcher with something like sintered mufflers. Or at very least, put a whole chicken on it and test it, before putting it in the field. See if any small bones break.

[Spider!]

Yeah, anything really good would be a hearing hazard. Even a muffler on a big blast doesn't guarantee safe levels.

Actually, you just need a rainmaker with a loudener

[Roger7pball]

NASA uses liquid propane cannons to get birds off the runway. Just an option if you’re unsuccessful in using compressed air.

[SEAR]

I'm not familiar with the valve from Havok and I cannot get any in Europe :/ Do you have any picture or diagram, Spider? I am well aware of the compressed air power - I won't risk any injury. That is why I won't use any combustibles inside either.

I plan to play with the sound signature only after I make a working prototype. It might be enough right from the start. My current idea is to use a very simple backflow valve pressed open by the downwards movement of the mine's upper cover.

One day, with all our equipment, we will be a very formidable AT unit

[Spider!]

https://youtu.be/ZXdF1vO60to

[russc]

If your goal is to create a big "bang" rather than a "whoosh" sound, you could make a much safer system with less gas pressure and volume if you design it around expendable burst discs. Your valve would actuate and fill a reservoir that is capped with a thin aluminum or copper disc, which you could stamp or try to buy off-the-shelf. At a certain pressure, it would rip through the disc and make a loud sound. Because it captures the gas and releases it instantaneously, it will make a sharper sound and will need less pressure and volume.

[Mishotaki]

personally, i'd look into converting a tshirt launcher: https://www.tshirtguns.com/index.htm
it's got to have a pretty decent amount of air to move a high volume object...