My Generation II Hybrid Fueling Tank

Postby markfh11q » Tue Nov 07, 2006 5:16 pm

First off, I'd like to say my thanks to DR for inventing this system, even if it does seem kind of simple now.

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This is my fuel mix over water compression tank for use on my next project. As you can see, the hybrid is going to be kind of small. The chamber is 8" of SCH-80 1-1/4" seamless steel pipe.

The tank is made up of 12" of 2" SCH-40 PVC, with an endcap on the front and a threaded adapter and male plug on the back. The meter consists of a 1/4" x 6" SCH-40 steel pipe nipple which can fuel the tank up to a 2x/2 atm mix. I also added a small drain cock at the bottom to drain water after filling.

The water input is going to be from a modified bike pump with an input from a 2 liter camelback bladder work in a backpack. I don't want to use a garden hose, but if I have to, I've got a swivel female garden hose x 1/4" MNPT adapter I made.

I decided to fill the tank to 2 atmospheres for two reasons:
1.) I didn't want a huge 3" tank
2.) I need a way to mix the fuel mixture. A fan would get water in it, so I figured the injected air compressing it to a 2x/2 atm mix would mix the mixture good enough.

As you can also see, I don't have a Schrader added yet for air injection. I'm going to wait till I order all the steel from McMaster and get a threaded one from there.

Tell me what you think!
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Postby SpudStuff » Tue Nov 07, 2006 7:41 pm

You should only put a 1x mix of propane in the tank otherwise you will have the same problems as the satandrd design. Looks good. Are thoes QC's on the outlet.
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Postby BewareOfDog » Tue Nov 07, 2006 10:48 pm

Uhhh... Why would you need a schrader valve for "air injection"??? Or am I missing something blatantly obvious?
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Postby markfh11q » Wed Nov 08, 2006 6:31 am

DR - Instead of filling the tank with just an atmospheric compression mix, I'm filling it to a 2x mix to get more shots out of it. I know fueling accuracy will go down a little because of this, but I'm taking a fluid volume of EVERYTHING once I get the gun assembled, so hopefully not by much.

SpudStuff - the hosing is a 1/2" FIP x 1/2" FIP faucet connector hose. The ends swivel, which is why I liked it. The tee at the end of the hose is where the whole fueling system goes into the higher pressure operating system, which is composed of the chamber, barrel, and inlet for the ignition system. They're shut off from each other by a check valve and a ball valve.

EDIT: just added a normal rubber Schrader. Could've used a threaded one, but I didn't see why for some reason just this morning.

Thanks for reminding me DR.
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