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This valve started as a one inch diaphragm valve that has a bad cap and diaphragm. So, starting with just the valve body, I machined a cylinder and piston to convert it to a proper piston valve. I recently blew the diaphragm in an identical valve at 600 psi. So, I wanted to see how much pressure I could reliably run through this style valve with a machined aluminum piston and cylinder. Well, I have fired and fired and fired this thing (dry firing as you see it) all the way up to 750 psi without any problems. This thing sounds like a bomb when fired!

I have disassembled the valve numerous times looking for any damage or signs of premature wear and none are present. I am VERY pleased with this valve. I plan on making a one inch bore cannon with this valve firing slugs at 800 psi.

This valve is an experiment used to aquire knowledge on piston design and dynamics for my upcoming HPA coax pistol.

Anyway, enjoy the pics........

Matt

Excellent job! It would be interesting to compare performance with the standard diaphragm valve.

Nice. I've only seen it done one other time. Great work.

You could make quite a profit off of selling modified valves

A 1" 750psi rated valve could sell for $200...

Hmm, I would wonder about the liability.

The big issue is, the valve body of this is $55. The pilot valve is $80, and the rest of the machining would cost about $55 to $65 more.

This stuff does get pricey.

Matt

Liability is not an issue if you're selling "no nonsense irrigation valves" just put a disclaimer not to use them for anything but proper commercial/industrial applications. Anyway, I feel they'd be very popular without the pilot valve if you could figure out a way to bring the price down and still make some money for yourself

Beautiful work! I wouldn't be surprised if someone with a fair amount of cash laying around was interested in buying from you. The Ultimate Spudgun store seems to show that people do indeed pay for quality.

Yup, an all-metal version of a "standard" sprinkler valve cannon would certainly look pretty cool

I am in the process of converting my 1/2 inch bore rifle to use this valve. I will report back on the performance when I have more data.

I have fired the valve at over 800 psi at this point and it operates wonderfully.

Like anything, there are benefits and drawbacks to any design. My big 2 inch cannon cost me about $500 to build, but is good for 400 psi and over 2,000 ft pounds of muzzle energy (you would be shocked how much kick that thing has. It is literally painful to shoot). But, I would have to get $1,000 or more for it to be worth the work it took to build. Plus, how do you air the darn thing up? I had to build a compressor to do the job. It gets pretty involved when you go over about 150 psi. But, that is where the fun really begins.........

I already manufacture products for resale. I have been through the production and marketting process. I am fine building stuff to resell. I just want to make sure everything is fully tested and refined before I would take that step on this.

I appreciate the kudos, though. I am also open to suggestions. I know this type of valve tends to have much turbulence through it due to the design. But, at these pressures, that condition is mitigated.

Matt

I am also open to suggestions. I know this type of valve tends to have much turbulence through it due to the design.

Why not go for the ultimate and dispense with the valve altogether?

The compound rounds by USG would make and ideal basis for such a project, and in terms of performance there's no better valve than no valve at all a burst disk would yield similar performance, but is a pain in the buttocks to replace.

I've only seen it done one other time

I still keep it in my workshop...
Just a 1/2" one ...but still..

Looks awesome!!
Much better than mine really!

Do you have any pictures you can post?

Matt

Here is the only one I have.
It is taken from a valve manufacturer's magazine ( Bürkert) featuring my report on the aircannon demo I did at the European Chunkin event for wich they had supported me.

It can be seen in the middle pic on the right.

a nice sidenote is that one year later they allowed aircannons to compete in the actual competition.
Without me...