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Manometric metering help

Posted: Sun Nov 02, 2008 5:03 pm
by Dave_424
I was wondering if this would be a good setup for metering my paintball tank hybrid:

paintball tank => threaded to a 1/4" ball valve => 1.4" tee with a gauge at the top and a male quick connect at the back

What range of pressure for the gague would I want??? 0-1 BAR ect.

Also if you have a better idea for setting up all of the fittings just give a suggestion

Thanks Dave

Posted: Sun Nov 02, 2008 5:11 pm
by ALIHISGREAT
for the guage it depends on the maximum mix number, so for 5x you could get a 0-4 bar guage.

Posted: Sun Nov 02, 2008 5:15 pm
by Dave_424
because I would only really use my compressor (8 BAR) which means a maximum mix of 9

I would only prorably only use about 5 or 6 mix but would like the 9x mix capability

Would This mean that I would have the buy the 0-7 BAR gague from airlines-pneumatics? would it be reliable to read the correct PSI at the lower pressures for lower mixes?

Dave

Posted: Sun Nov 02, 2008 5:18 pm
by DYI
A 0-15 psig fuel gauge is adequate for mixes of up to 20x, or thereabouts. You can buy +/-1% accuracy ones from McMaster-Carr.

Posted: Sun Nov 02, 2008 5:27 pm
by Dave_424
How would a 0-15 PSI gague work?

OOOOOOOH would I just use the 0-15 PSI gague for adding the propane to the chamber, But how would I know the PSI that I would be adding from the compressor? Set the regulator for that mix?

If anyone could clear this up it would be a great help

DAVE

Posted: Sun Nov 02, 2008 5:57 pm
by Fnord
Alihisgreat gave you some fuzzy or inaccurate info, but DYI got it right.

For a 20x mix, you'd need about 15 psi of propane pressure on the gauge, or one chamber volume of propane. For 9x, you'd want about 7 psi, maybe a little less. You'll need to add the propane pressure to the total air pressure you're going to add, otherwise your mix will be off a little.

Posted: Sun Nov 02, 2008 6:09 pm
by SpudFarm
no need for the expensive gauges. mine works a treat with a cheap one (0-1bar)

Posted: Sun Nov 02, 2008 6:17 pm
by Dave_424
I have decided on how I am going to do this

chamber => 1/4" ball valve => 1/4" tee => 0-11 BAR gague on top => on end a male quick connect (This is the set up for oxidizing) then for the fueling

Female quick connect => 1/4" tee => 0-1 BAR gague on top => propane source

Dave

Anyone know where to get the propane tank hreads - 1/4" adapter?

Posted: Sun Nov 02, 2008 8:25 pm
by Larda
I used a single 5000PSI +-0,02% digital gauge to meter both the propane and the air for my hybrid, (0-20% of full scale= +-0,02%, 20-100%full scale=+-0,1% of reading).
I have used it from as low as 5x up to 200x without a problem.
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Posted: Mon Nov 03, 2008 9:37 am
by SpudFarm
Dave_424 wrote: Anyone know where to get the propane tank hreads - 1/4" adapter?
i just went out to a little pipeshop "a really SMALL one!" and brougth my propane tank and said "do you have a fitting so i can get 1/4" threads on this tank?" it is a pretty normal part around here and they will almost certainy have it ;)

Posted: Mon Nov 03, 2008 11:30 am
by Dave_424
So would B&Q have the right fitting?

Anyone know of a place online to get one? i can't find one anywhere.

Dave

Posted: Mon Nov 03, 2008 6:07 pm
by psycix
Dave you could also use two different gauges: a low one for measuring fuel precisely, and a high one for measuring the air pressure.
Make sure to use a ballvalve to protect the low pressure one from higher pressures.


@ Larda,
And what would one pay for such a beauty hmm?

Posted: Mon Nov 03, 2008 6:24 pm
by Dave_424
Yes Psycix in a post a bit above I have a 0-1 BAR gague on the detatchable fueling meter and then a 0-11 BAR gague permanantly attached to the chamber, with a isolating ball valve of course :P

Anyone else with an idea to get an adapter in the UK for a propane tank to 1/4" threads?

Dave

Posted: Tue Nov 04, 2008 2:33 am
by ALIHISGREAT
you could probably get an 8mm compression fitting on there which i think has 1/4" threads, you really need to get hold of your propane tank first, then its a case of whatever fits.

i thought about sticking the lever locking schrader adapter off a pump on the tank then i could easily fill through cored shcrader.

Posted: Tue Nov 04, 2008 2:51 pm
by SpudFarm
psycix wrote: @ Larda,
And what would one pay for such a beauty hmm?
from MY memory it was about $900 or $250...

pretty sure it was the 900 one.

i also think that it is the kind of gauge that does 5000 readings per second :D