"Overkill" New 1.5'' Piston valve in progress! Vid

[jhalek90]

EDIT:

photos of the new 1.5'' porting piston valve in a 2'' T:



ALL photos/ videos below this text are with the 3/4'' valve.
2'' videos comming soon, still need to have the 2'' nipple welded onto the chamber.

100 psi video
[youtube][/youtube]

200psi video
[youtube][/youtube]

EDIT: I believe the "Squeak" at the end of the video may be caused my ice forming around the barrel port of the cannon. The piston is not spring loaded, so it stays open, but the valve "leaks" air out the barrel at a respectable pressure, for about 30 seconds after each shot.

125 psi of air in a MASSIVE scuba tank
3/4''porting metal piston valve.
yay!

That tank weight about 45lbs empty. it opens with a LOUD bang, and air rushes out so fast the valve freezes if shot at more than 125 ish PSI.



Just thought i would share this with you all.
Now i just need to find a 100' barrel...

EDIT: It takes about 45 seconds to one minuet to fill from my shop compressor, to 125 psi. I would love to shoot this at 500psi, as the valve is all metal, but i doubt my friddgy would survive pumping this up to 500 PSI. any ideas?

[Gun Freak]

Holy god... At 500 psi and with a 20 foot barrel that thing will be a monster

[jhalek90]

Yeah, i cant wait, i just need a way to FILL it to 500 psi.

Think my friddgy will survive?

[Gun Freak]

I think it would, might take a while but as long as you give it a long break in between shots (by long I mean like an hour ) it should be fine.

[jhalek90]

yeah. I will have to wait and see.

[jackssmirkingrevenge]

Epic! Looks like the fridgy might need some help on the input to push it along though, and some kind of cooling system along the way.

[jhalek90]

The friddgy is running. Aprox 10psi every 5 minuets.

I pre filled the tank to 125psi.

DONE: 200 psi shot. took about 30 minuets to fill.

200psi video
[youtube][/youtube]

Edit, i just wanted to pint out that the flow of this valve is limited by the size of the hole in the neck of the cylinder, which is just slightly smaller than the barrel port on the valve.

[POLAND_SPUD]

but the valve "leaks" air out the barrel at a respectable pressure, for about 30 seconds after each shot.

or the rapid decompression cools the gas inside... as the temperature comes back to normal the air expands

i doubt my friddgy would survive pumping this up to 500 PSI

what's the capacity of the tank?? (volume)

some kind of cooling system along the way

liquid cooling

find a bucket slightly larger than the compressor and fill it with oil...

[jhalek90]

what's the capacity of the tank?? (volume)

Not sure. it stands about 3 feet tall, and is about 6'' in diameter.
So approx 1000 cubic inches. Not counting for wall thickness.

liquid cooling.

Or cool it with the muzzle blast..... lol.

[POLAND_SPUD]

So approx 1000 cubic inches

OMG
http://www.schooltube.com/video/c9eb3ad ... ric-system

[Technician1002]

Epic! Looks like the fridgy might need some help on the input to push it along though, and some kind of cooling system along the way.

Actually this can overload the motor and overheat it. Pick up an AC amp meter and monitor your compressor current while filling. Try to keep the current no more than 10% above the FLA value marked on the nameplate. You can control the load on the compressor by "throttling" the inlet pressure.

As the output pressure rises, lower the inlet pressure to unload the compressor. For higher pressure it is a good idea to use a small displacement compressor designed for higher operating pressure. In that regard you want to use an Air Conditioner compressor as it is designed for higher outlet pressure due to the higher outside temperature than a fridge. To do even better find one that uses a higher pressure refrigerant too. A compressor designed for an air conditioner that uses R22 instead of R134a will have a smaller displacement and is designed for higher operating pressure.

You need a bigger valve for that chamber JSR.. I'll have to shoot a video of just the tank and valve operating at 100 PSI on my 3 gallon. The 2 inch valve doesn't take long to empty a 3 gallon tank.

EDIT. For the Capacity of most compressed gas cylinders, you find the stamp in the metal that is Marked WC. That stands for Water Capacity. The number is the weight of water that the tank will hold. In the US this is measured in Pounds.

I believe there is a metric equivalent.
http://en.wikipedia.org/wiki/Gas_cylinder

[daniel0663]

WOAH,
Thats awesome.
Build a 2" valve for it.
It will be EPIC :wav:

[jhalek90]

A 2" valve would be a waste, ad the flow is limited by the 3/4" hold in the neck of the bottle.

[jor2daje]

with a long barrel wouldnt a ball valve actually be more efficient?

[Gun Freak]

It wouldn't be more efficient... It would just make up for the slower opening time. If the ball valve had a bigger port then it might even have better performance than the piston valve.