Chamber Sealing Diaphragm Valves

noname · Mon Apr 23, 2007 8:20 pm

I'll build one of these for an upcoming cannon, but I just posted a diagram anyways.
According to some people, it's impossible to build a chamber sealing valve without O-rings. I proved you guys wrong when I thought this up on vacation. It probably won't have as good of flow as a barrel sealer would, but this makes it possible for me to use a Vogt pattern barrel. Credit partially goes to hi, becase he said a diaphragm is placed in a union. That made me think.
The valve is basically a barrel sealer with the diaphragm in a union, with an equilization port going into the chamber.

Hawkeye · Mon Apr 23, 2007 8:27 pm

You prove us wrong when you build it and show it works. I can see a problem...

noname · Mon Apr 23, 2007 8:29 pm

And exactly what is this problem you speak of?

Velocity · Mon Apr 23, 2007 8:30 pm

Hawkeye wrote:You prove us wrong when you build it and show it works. I can see a problem...

Why not tell him what the problem is?

Anyways, I really like this design; it is incredibly unique, and it will open up all sorts of possibilities for those of us who can't build chamber sealing valves. Make sure to add a spring behind the diaphragm though to help it seal.

And BTW, couldn't you just make a Vogt pattern gun if you used a barrel sealing piston valve connected directly to the chamber with no 90* turn, and then attached the Vogt pattern assembly on top of that?

noname · Mon Apr 23, 2007 8:34 pm

Rmich, thanks, I did forget the spring, although it may not need one because I'll fill through the pilot side. I couldn't use a barrel sealer in the configuration you're talking about because the chamber has a 180* turn in it, making it a "stationary cannon" type thing.

Velocity · Mon Apr 23, 2007 8:46 pm

noname wrote:...the chamber has a 180* turn in it, making it a "stationary cannon" type thing...

I am not sure what you mean here.

<img src="http://www.spudfiles.com/uploader/uploa ... LOADER.JPG">

You couldn't just arrange the cannon like this? If you are planning on submitting your cannon for the contest, then I will just find out what you mean when the time comes.

noname · Mon Apr 23, 2007 8:49 pm

Exactly what I can't do. The bottom of the valve and the fill/exhaust system would get in the way.

Velocity · Mon Apr 23, 2007 9:33 pm

You could always build a valve like the one in your signature

... Just kidding

Hawkeye · Mon Apr 23, 2007 9:45 pm

When the diaphragm bows forward to seal the chamber will air not be able to leak around the edges? That would prevent the pilot from holding pressure wouldn't it?

boilingleadbath · Tue Apr 24, 2007 3:33 pm

It's not terribly unique... it is my understanding that many sprinkler valves are chamber sealing.
Not that we have a lot of home-made chamber sealing diaphram valves...

iknowmy3tables · Tue Apr 24, 2007 4:23 pm

wow I was just thinking of some thing similar actually I was thinking more twords pistons, but fist I 'd recommend using some kind of flangs or bolt on thing like a sprinkler valve, second a great application is for reusable pneumatic bombs like with paint or flour for senerio games, just look at it differently in stead of it being in a tee with one outlet imagine a pipe with a bunch of holes and the load being in it it would shot out of every hole, this is just my look at this you'll might differ

noname · Tue Apr 24, 2007 7:20 pm

Hawkeye, that's why it's in a union.
BLB, I have yet to see a chamber sealing sprinkler valve, and I ususally buy any I see from the hardware store or whatever, take it home, take it apart to see how good flow would be, and if it sucks, I return it.

clide · Wed Apr 25, 2007 12:01 pm

I wouldn't say there are a lot of chamber sealing sprinkler valves, but they certainly aren't rare. The jar-top Watermaster is fairly common and it's a chamber sealing valve, pics can be seen http://www.thehalls-in-bfe.com/GGDT/lib ... 1_mod.html

I'm pretty sure I've seen quite a few others as well, but I can't remember the models.

Your design should work as long as your diaphragm is strong enough and the union is tight enough, but since you have to make the chamber outlet go all the way through to the other side of the tee flow will be limited. IMO it would be worth it to try some of the various latheless o-ring groove methods and make a piston and have a bigger sealing port.

Although if you just want to do it because it hasn't been done then I can understand that...that's why half of my guns were built.

noname · Wed Apr 25, 2007 4:38 pm

Clide, your first point is true, but I haven't been able to find that particular valve at Ace, OSH, or Home Depot.

"Although if you just want to do it because it hasn't been done then I can understand that...that's why half of my guns were built."
You hit the nail on the head.

Chamber Sealing Diaphragm Valves

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