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Pneumatic Air pressure

Posted: Sat Sep 25, 2010 11:50 am
by KingKyro
I just built my first Pneumatic gun and i was wondering what are the warning signs if any that i need to be aware of so i don't put to much air pressure in my chamber.

Posted: Sat Sep 25, 2010 11:52 am
by urgle the danish cow
if its pvc read the pipe to be extra safe and if you are using a ball valve read the valve for max psi

Posted: Sat Sep 25, 2010 11:58 am
by Gun Freak
We need to know what kind of materials it is made out of. PVC, if sch 40, is normally used at about 100 psi. Sch 80 is rated higher and can even be used in low mix hybrids. If it is metal, like galvanized pipe nipples, then it will be good at I'd say a max of 800 psi but I wouldn't push it higher. So and pictures and/or details of the gun would help us answer your question...

Posted: Sat Sep 25, 2010 12:20 pm
by KingKyro
here is a few picks of the chamber and valve assembly. i didn't include the barrel cause i made it interchangeable, all my PVC pipes are pressure rated.
My downfall is the end cap, coupling's and other attachments i had to buy didn't say if they where pressure rated or not.

Posted: Sat Sep 25, 2010 12:40 pm
by Gun Freak
With that way you drilled into a single layer or pvc three times, I would only trust this launcher up to 100 psi. Some people may suggest even lower :D How high have you been using it?

Posted: Sat Sep 25, 2010 12:40 pm
by clemsonguy1125
The only problem I see is that you tapped the gauge into a single layer of pipe. If not for that I would say 80 PSI, but since you did personally I would rebuild it but at 30 you MAY be safe. Other than that nice, clean first pneumatic.
Edit-Gen Freak beat me to it but trust me, 100 PSI is not a good idea

Posted: Sat Sep 25, 2010 1:07 pm
by Technician1002
Very good performance can be had if you didn't use a small restrictive valve between the chamber and barrel. Best performance is had when the valve is at least as large as the barrel. A 1.5 inch valve will out perform a 1 inch valve by about double. A 2 inch valve is often cost prohibitive. Price skyrockets with larger sizes.

Posted: Sat Sep 25, 2010 1:12 pm
by Gun Freak
@Tech, AFAIK, 1.5" sprinkler valves are not all that common.

Posted: Sat Sep 25, 2010 2:36 pm
by Technician1002
@ Gun Freak, I must be lucky. One store near hear even has 2 inch for about $80.

Posted: Sat Sep 25, 2010 2:45 pm
by KingKyro
@ tech, i had to order the 1" valve off the internet cause i couldn't find them in any stores around me. i tried Lowes, home depot and a few others. as for the gauge i had wondered if re doing the chamber so the gauge goes through the end cap and inner PVC would be better but wasn't sure. so far Ive had it up-to 60psi using a bike pump, didn't hear no leaks or anything, all i noticed is how hard it got to pump at that point. if i make the chamber shorter when i re-build it will that affect the amount of pressure i can use?

Posted: Sat Sep 25, 2010 6:31 pm
by saefroch
No, shortening the chamber will not affect the level of pressure the pipe can take. It will affect performance though.

Posted: Sat Sep 25, 2010 7:03 pm
by Technician1002
KingKyro wrote:@ tech, i had to order the 1" valve off the internet cause i couldn't find them in any stores around me. i tried Lowes, home depot and a few others.
This is strange. My local Home Depot has them in the Irrigation isle. Their online website lists several models that are in your local store and not for online purchase.

Model 57101 and 57100 on the page below indicates this. Don't look in the plumbing section. Check the irrigation isle for the yard and garden.
http://www.homedepot.com/webapp/wcs/sto ... ogId=10053

Image

Posted: Sat Sep 25, 2010 7:44 pm
by KingKyro
This is what confused me tech, i can easily find the valve on the company websites but they didn't have them for in store sale. I even had manager's looking for me in the isle's as well as on there computer's.they all came back the same online purchase only. maybe its a Pennsylvania thing i don't know.

Posted: Sat Sep 25, 2010 9:48 pm
by maverik94
This is strange. My local Home Depot has them in the Irrigation isle. Their online website lists several models that are in your local store and not for online purchase.
My local Home depot doesn't carry sprinkler valves either. I just order mine from Amazon.com :)

Posted: Sat Sep 25, 2010 11:49 pm
by Technician1002
I wonder if they don't carry them in locations that are always wet and humid and don't use irrigation.