SpudFiles

alright, my mate and i got the pvc today. damn those fittings cost a lot!

im gonna mod the valve, and i found a blow gun at supercheap for about 4 bucks (it was on sale ) but it had a shiney holographic sticker saying WARNING: 90 PSI MAX. should i be worried about using this thing? ive read threads saying that the pressure rating on the blow gun means jack all, but this sticker is a little to obvious to be ignoring atm. the chamber will be at around 120psi and wont go over 150psi ever.

another thing, i couldnt get a fitting to go from a 50mm to a 25mm, but i managed to get a few bushings to make what i want. i used a 50x40 bush then a 40x25 bush with a 50 coupling. i was wondering if this was going to cause a design flaw or make the chamber overall weaker.

any comments or suggestions welcome.

I have a blowgun that said was rated for 90psi but i took it all the way to 250psi without any leaks. Although when it is that high it becomes really hard to pull the trigger on it. I wouldn't take it that high with a large chamber in case it blows.

But I have also had some blowguns that leak down to 90psi if they are pumped above it.

That is all I have to contribute, sorry I don't know anything about making pvc chambers.

thanks alot mate, i guess ill be getting that shiney blow gun

This is the type of blow gun that I used that works well at high pressures. You can easily unscrew the point to allow more flow.



Don't use this type of blowgun from a tire inflater, it will leak if it gets over 90psi.

The design should be perfectly fine.The 50x40 then 40x25 is what I use mostly unless I can find a 50x25 bushing,which isn't very often as they are not found everywere.

More to the saftey of the cannon is what type of pipe PN are you going to use?I personaly recoment PN12 as minimum.

As to the blow gun dont worry at all,it should hold up fine my Blow gun had a rating max of 70psi and I readily take it to 130psi which is nearly double the "max" pressure.

What plans are you going with for your gun?Over under,inline,sniper?Barrel size etc.I may be of some help as I am an Aussie aswell and if you are unsure about something then just give me a PM .

I thought this would be a fitting question considering the title of your post is "fittings". I was wondering what the most highly used, (a.k.a. cheap/reliable) website/store for buying pressure rated pvc fittings... surprisingly, Home Depot does not sell pressure rated fittings.

pyr0 wrote:I thought this would be a fitting question considering the title of your post is "fittings". I was wondering what the most highly used, (a.k.a. cheap/reliable) website/store for buying pressure rated pvc fittings... surprisingly, Home Depot does not sell pressure rated fittings.

Yes they do.
I have never been to a home depot that doesn't have some form of pressure rated fittings.

sorry guys, just got back from camp so i havent got the chance to post.

rna_duelers:
i am using pn12 pipe with all pressure rated fittings.
the design of the gun is a simple over-under "sniper" config: 50mm chamber, 25mm connections from chamber to modded sprinkler to a 20mm breechloader barrel. the breech is simply a 20mm coupling shaved to slide over the 20mm pipe with the ejection port cut with a dremel sealed wtih a rubber washer and o-rings. a wooded stock will be moulded to fit in between the chamber and barrel to create a stable design. pictures speak a thousand words so ill post a working progress picture of the cannon assembled just not cemented soon.

thanks to everyone for their help with the blow gun and bushings.

pyr0 wrote:I thought this would be a fitting question considering the title of your post is "fittings".

integral wrote: another thing, i couldnt get a fitting to go from a 50mm to a 25mm, but i managed to get a few bushings to make what i want. i used a 50x40 bush then a 40x25 bush with a 50 coupling. i was wondering if this was going to cause a design flaw or make the chamber overall weaker.

looks like a fittings question to me, read the post before commenting

integral wrote:...but it had a shiney holographic sticker saying WARNING: 90 PSI MAX. should i be worried about using this thing?...

I find that rating is only for when you are using it for blowing stuff around with the nozzle. That warning is probably just in case something comes out of the compressor (like a water droplet) and flies at 500 fps towards your eye!!!

...Or just so they don't get sued when some idiot somehow manages to do something stupid with it.