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Use of sprinkler valves at high pressure

Posted: Sat Aug 02, 2008 3:56 pm
by skyjive
So I have a rather unsuccessful 1/2 inch copper piston gun that I am thinking of refitting with a sprinkler valve. The gun fills off 12g CO2 cartridges and uses chamber volume to set pressure (hope my math skills are up to snuff...). So my question is, has anyone taken a sprinkler valve to 150 psi or above? what kind of safety factor will this give me? Would the diaphragm, blowgun, or valve body fail first? How will valve performance be affected? And also, will using CO2 instead of HPA have any negative consequences? I did do a search before posting this and it seems to me as though 150 is pushing it but essentially OK, but I figured better safe than sorry and I'd check it out in this post even at the risk of repeating previous topics. Thanks for your help.

Posted: Sat Aug 02, 2008 4:05 pm
by SEAKING9006
150 is DEFINITELY pushing it, and thats with anything PVC at that pressure. My suggestion is get one as small as they come, and mod it with a fully modded blowgun. If you are open to other valve types, use a QEV. They are common in stronger materials.

Posted: Sat Aug 02, 2008 6:05 pm
by TurboSuper
I've taken mine to 120 PSI without incident. It says on the packaging not to exceed 80 though, I wonder how big the safety margin really is...

Posted: Sat Aug 02, 2008 6:22 pm
by SpudFarm
i would guess there is a 3:1 marginal..

Posted: Sat Aug 02, 2008 6:40 pm
by MrCrowley
Seeing as diaphragm QEV's can well widthstand their 125psi pressure rating up to over 700psi, I would think sprinkler valves are relatviely safe at 175psi.

Unlike PVC pipe and fittings glued together, the valve is just one piece of molded plastic and it's quite thick. It should hold 200psi easy. But the 'phragm will probably be the first to go, it could rip, tear or just overall fail at such pressures, but I doubt it will fail at 175psi.

Posted: Sat Aug 02, 2008 7:00 pm
by SpudFarm
nr_crowley- it is screwed together and the cap has quite big surface area

Posted: Sat Aug 02, 2008 7:05 pm
by MrCrowley
Oh right so you think the lid will pop-off?

That's something more plausible but I still think that it will be fine at 175psi. I don't recommend it, but I don't think it will fail that low either.

Posted: Sat Aug 02, 2008 7:09 pm
by SpudFarm
well it is only one way to find it out.. pressure testing

Posted: Sat Aug 02, 2008 7:17 pm
by Mr.Sandman
if you do, it put it underwater or under a box filled with t-shirts nah im just messin with ya :D anyways what brand of sprinkler valve is it and instead of using a sprinkler valve spend a cuple bucks and upgrade to a qev so you can take ot to higher pressures

Posted: Sat Aug 02, 2008 8:51 pm
by Darkside 6ix
Well ive never brought any of my valves over 100psi because I have a pump thats being held together by duct tape (not really, but it gives you an idea of how crappy it is) So when I get a compressor, i would like to know how high it is safe to take it

Posted: Sun Aug 03, 2008 12:39 am
by jon_89
i have used mine to 160psi.

Posted: Sun Aug 03, 2008 1:21 am
by daxspudder
Ive heard of them being used as high as 350 before. Their construction is rather durable, and the 3/8"thick lid is more likely to split than strip all 8 screws threads, and if its modded, the quality of the mod is a factor(ive blown a blowgun off my valve twice). Most blowguns are only rated to 90psi, and a standard home depot bought watermaster 1" sprinkler valve is rated at 120psi, i personally have taken mine a little over 220, and I think anything under 350(really just pulling that number out of my ass) is safe(doesnt mean im gonna do it)... just remember the really large, flexible diaphragm always has some pressure on both sides, and over 90psi the blowgun will shut slowly, if at all, allowing the diaphragm to re-seat slow enough that 100psi+ pushing down on it wont destroy the seating diaphragm itself. The real failure point is the point in which the pressure pushes the rounded barrel riser through the lower seating diaphragm, which i estimate to be around 400(why i think 350 is safe, but still a guess)