Page 1 of 1

Hybrid Ball Valves

Posted: Wed Nov 10, 2010 8:34 pm
by Grignacke
Hey guys. I'm building a hybrid, plan to take it up to 10X - 15X, and I have the fueling system inline with the chamber, as with other cannons I've seen in the showcase. Thing is, will a ball valve between chamber and fueling system have to be steam rated, or will a rating for inert gases suffice? In addition, what kind of pressures do you expect from a hybrid upon ignition?

I also have a couple of other questions, mainly so I don't die / waste oodles of money.
1) In fueling, I read the sticky on the subject, and I understand how to put propane inside and how much I need depending on chamber volume, but when filling it with air to compensate for the extra propane, since the pressure gauge I'd be going off of is either on the compressor or is the same meter that I'd be using for propane, should I take into account that the pressure of air is both chamber and brass fittings that are the fueling system?

2) Does the fact that a hybrid is essentially an artillary piece necessictate
some sort of permit / legal documents? I mean, if I go to a secluded place to fire, then no one will most likely care too much, but just to be on the safe side... :P

Phew. That's alot of q's. Thanks in advance, and have a great week, guys!

Posted: Wed Nov 10, 2010 9:15 pm
by Zeus
Well I think downloadingHGDT might help.

Also, fire the hybrid somewhere people will think that it's a 12 gauge, the further away from non-spudders, the better.

Have fun

Lachlan

Posted: Wed Nov 10, 2010 9:34 pm
by Grignacke
Is there a HGDT for mac? I checked it out awhile ago and it said he had not porting to mac D:

Posted: Wed Nov 10, 2010 10:25 pm
by Crna Legija
the preessure will be about 100psi per x so for 15x its 1500psi. It would be a bit less but better safe then, well dead.

Posted: Wed Nov 10, 2010 10:35 pm
by ramses
Grignacke wrote:Is there a HGDT for mac? I checked it out awhile ago and it said he had not porting to mac D:
no. you could try WINE, an emulator, virtualbox, bootcamp, etc.

sooner or later you'll see the light and go windows (or linux)

I use whatever ball valves are sold at Home Depot ($5) and ace ($10!!!)

The 1/4" ball valves at Harbor Freight are really cheap and rated to 600PSI like the rest of them. I may buy 5-10 next time I go. They're seriously that cheap. The ball valve is probably one of the least likely components to blow, as long as you use a small one. Someone blew the seal on a 1"-2" one in a hybrid, but they're still alive. :D

Posted: Thu Nov 11, 2010 6:30 am
by Grignacke
For the record, I do have an opensuse machine that only boots in safe mode... Muhahaha

Posted: Thu Nov 11, 2010 4:05 pm
by qwerty
the preessure will be about 100psi per x so for 15x its 1500psi. It would be a bit less but better safe then, well dead.

You sure about that?

I always thought a 1x mix was 4% gas and the normal atmosphere
2x = 8% and 14.7psi
3x = 12% and 29.4psi

I know that isn't perfectly accurate but it's along those lines i think.

so a 15x would be about 147psi not 1500.

Posted: Thu Nov 11, 2010 4:10 pm
by MrCrowley
He's talking about peak combustion pressure, not pre-ignition pressures.

edit: Pre-ignition pressures for a 15x mix would be over 200PSI by the way, not 147.

Posted: Thu Nov 11, 2010 5:46 pm
by ramses
147 would be an 11x mix, ignoring the pressure of propane, which is about .62 PSI per X. It makes a difference.