Un-Regulated CO2

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Lockednloaded
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Sat Nov 13, 2010 8:19 pm

For me, un-regged co2 is my only source of high pressure in pneumatic, but I'm not sure what parts can handle it.

QEVs have been used way above their pressure rating of usually ~125psi, but the information I've found conflicts. some say never above 30bar, but other claim to use them up to 58bar. I can't trust results that don't match, so I need a conclusion: is there any QEV that can handle un-regged co2, it can be the standard european ones, the square ones, or the american ones found on mcmaster. I have access to all of them, I just don't know which would hold the highest pressure.

Thanks for the help, but in the responses, I would prefer answers with info/numbers/experience to back them up.
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Sat Nov 13, 2010 11:08 pm

LnL wrote:Thanks for the help, but in the responses, I would prefer answers with info/numbers/experience to back them up.
I don't recall anyone ever making the claim of full on unregulated C02 on any type of QEV valve. Some members make claims of using piston valves with unregulated C02...

The only certain thing I can say is if you test, take all necessary safety precautions when doing so.

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Lockednloaded
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Sun Nov 14, 2010 12:09 am

Just found one, jeepkhan's decimater, it seems to be a european style one, but I can't totally tell
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Sun Nov 14, 2010 1:09 am

Small point to note about unregged co2....it can reach FAR higher pressures than 850psi when/if it gets hot.

The storage bottles have an 1800psi rating for a reason. This is WELL beyond anything even I have hydrotested a qev to.

Dangerous waters LL.

IMHO, a piston valve designed with the pressures in mind is a far better option. At the very least, you'll at least know what the safety factor is.
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Lockednloaded
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Sun Nov 14, 2010 1:29 am

the maximum pressure they could reach on the hottest day is>1500psi, I have a gauge that goes up to that, and a pilot valve that can easily handle it

EDIT:
I wish jeepkahn would chime in here, he used one un-regged here
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Sun Nov 14, 2010 8:08 am

ive used a 1/2 piston qev up to 800psi about it was on a cooler day and it handle it fine but be careful that the co2 doesnt freeze thge rubber piston cause it could shatter like glass
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Sun Nov 14, 2010 10:09 pm

Lockednloaded wrote:Just found one, jeepkhan's decimater, it seems to be a european style one, but I can't totally tell
jeepkahn Posted: 12/24/2009 9:57 AM
My local fastenal stocks 3/4"(which I use well above 700psi on the decimater
This post doesn't actually state the max pressure he used and how many times. The term "Well Above" is certainly less than a precise unit of measurement
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Lockednloaded
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Sun Nov 14, 2010 10:17 pm

un-regged also infers a non-precise number, and he uses the word "unregged" to refer to his maximum firing pressure
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Mon Nov 15, 2010 2:11 pm

Lockednloaded wrote:the maximum pressure they could reach on the hottest day is>1500psi,
The tone and content of your post are contradictory. Assuming you meant to say "<1500", then the post makes sense, but I beg to differ. I've blown MANY an 1800 psi burst disc on CO2 tanks.
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Fri Jan 21, 2011 10:10 am

Going from temp and being unregged, I'm guessing around the 1200psi range... the main reason for the low rating of the qevs is the "piston" in them, and service life in industrial applications... the piston in some instances WILL fold itself backwards upon piloting, allowing the chamber pressure to escape through the pilot when fired without the barrel unsealing... I have yet to rupture one(causing an AD)... The fix for the "folding" piston is to use a 1/8" bolt and fender washer to add rigidity on the pilot side, and a flange nut on the outlet side of the piston... haven't folded one since, and haven't noticed any loss in flow or performance from the missing .023" of travel lost by the washer...

this being said, the difference in actual performance between unregged and regging at around 750 is NOT worth the extra co2 used by going unregged... I can't remember exactly but I think I calculated that it takes roughly twice the amount of co2 to go from 750 to 1000 on a 80degree day...
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Fri Jan 21, 2011 2:47 pm

That's really good to know jeepkhan, looks like you're saving me a lot of money on co2 as well as efficiency. I recently came into possesion of a female palmers stabilizer that goes to 700 psi
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