Popoff valve pressure

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
From_Hamsterdam
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G'day everyone it's been a long time.

Any way i am back and looking at building an auto some thing like this http://www.spudfiles.com/forums/full-au ... t4108.html

I need some advice on pressure relief valves:
can they pilot a sprinkler valve? or will i need a Q.E.V.?
what pressure will they activate at? (considering a standard off the shelf relief valve like from Bunnings) or will i have to get one some were else or modify it with a new spring

hoping to make the first fully auto cartridge gun :)
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Carlman
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the sprinkler will not seat fast enough i do not think thats why QEVs are really good at this. Im in WA and got my QEV from SMC Pneumatics
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From_Hamsterdam
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what do you mean seat fast enough?

i know qevs need less change in pressure to open so they would be a better choice, but i cant be arsed ordering one over the net so if this store is close i will certainly get one. well considering i drive from Joondalup to Belmont every day it is most likely close at some point.
What is the address of this place?

where in WA are you?
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frankrede
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Sprinklers don't close fast enough to be used in full auto cannons, unless you want a honking really slow ROF cannon
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From_Hamsterdam
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i cant see closing being a problem because i will fill from behind the diaphragm. i think opening will be a bigger problem.

any one know the pressure a compressor pop off valve would activate at?
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MrCrowley
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From_Hamsterdam wrote:any one know the pressure a compressor pop off valve would activate at?
I would say 125 or 150 PSI.
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jrrdw
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They come in different pressure ratings, I've read here they can be bought adjustable.
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MrCrowley
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Yeah it depends on your compressor. Most only go to 115psi or 125psi. So i'd guess they'd pop before 150psi.
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jrrdw
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Mine blows at about 100 now, they must get weak after time. My compressor is 6 years old now.
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mega_swordman
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If you go to McMaster you can get Pop-off valves at many pressures in 5 psi increments. I got a 90psi pop-off valve there a while ago.
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Carlman
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From_Hamsterdam wrote:what do you mean seat fast enough?

i know qevs need less change in pressure to open so they would be a better choice, but i cant be arsed ordering one over the net so if this store is close i will certainly get one. well considering i drive from Joondalup to Belmont every day it is most likely close at some point.
What is the address of this place?

where in WA are you?
im in padbury, 15mins from joondalup.

look it up on net

where bouts are you mate?
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From_Hamsterdam
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smc address:
Perth
Cnr Daly & Resolution Drive
PO Box 143
Belmont WA 6104

Cnr Daly & Resolution Drive are actually in Ascot so i think them made a mistake, turns out they are about 5mins from my office. i also have to get a small ram and a pop off valve hope they sell them.
if i cant get it at smc i will have to order one.

i live in Ocean Reef. I used to work at Jesters in Padbury you been there?
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Carlman
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From_Hamsterdam wrote:i live in Ocean Reef. I used to work at Jesters in Padbury you been there?
yea man all the time :D

yet another so close to me, watto is very close to me too.

we shall have to go spudding sometime
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From_Hamsterdam
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sounds good i have to finish a gun first, i tend to frankenstein any that are finished when building some thing new.

did you order your qev from smc or go in to the shop?
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jackssmirkingrevenge
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I had planned a cartridge fed sprinkler valve launcher as an evolution of this project that looked something like this:

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What sort of dimensions did you have in mind? You could go the BTB route and make a massive popoff valve as your main firing valve if this is for a small calibre ;)
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