Short question topic

[wdr0]

Clear Pvc with a nylon braid? That stuff is only rated for maybe 20 bar at the highest. You won’t find any 40 bar rated tubing at a hardware store. Easiest locally available would probably be hydraulic hose.

[Alex345]

Perhaps hose for a high pressure cleaner? EDIT: These probably have some kind of proprietary fitting so that's probably not an option. There are so many guys here using fridge comps, what do you guys use to connect it to your cannons?

[farcticox1]

Yes, we use stuff at work rated for 3000psi, 3/8 ID single wire reinforced, it is somewhat flexible. The ends are hydraulic crimped though.

It looks like this.

[wdr0]

That pressure washer hose would be a good option. Very similar to hydraulic hose. I believe most of the commercial stuff actaully has regular 3/8 pipe thread. The ones sold with home use electric units use a 22mm thread.

[Alex345]

Yeah but i think they are sold in fixed lengths, and this tiny fridge comp is already so slow. I'm now aiming more to replace the union fittings with high pressure QD fittings, perhaps i could keep using the copper tubing that way. Any idea on what the regular DIY store QD's can handle?

I could just keep the comp running until something gives way but i'd prefer to have a general idea on when these would fail. Because if the QD that supplies the pilot air would fail while the cannon is loaded and ready it would fire without me wanting it to. I still have some cheap brass ones lying around, but if they are unsafe i'll happily order some high pressure rated ones online.

[jakethebeast]

I have used just basic quick disconnects at 40bars without a problem. Only the "disconnecting" needs a bit more force than in normal 8 bar use

[Alex345]

I have used just basic quick disconnects at 40bars without a problem. Only the "disconnecting" needs a bit more force than in normal 8 bar use

My current fridge comp set-up allows me to bleed the lines before disconnecting so that should be no problem. Any difference between the brass ones and the RVS ones?

[jakethebeast]

Haven't tested them that far, just chucked in some random female quick connect to my fridgy when I wanted to test it out the first time and never bothered to change it to a proper foster fitting

[Alex345]

Allright thanks! I'll use a one-way female QD for the main chamber and a male side for the pilot, my fridge comp already splits into two lines so it's less of a hassle than it sounds like. The pilot is operated by a 1/4 QEV which again is piloted by a 1/4 solenoid valve so using a female QD for the pilot would not work anyway unless it's a free flowing one. Here's a pic of the basic concept:

Please don't mind the tape it's still in prototype phase

[wdr0]

If you don’t mind ordering than this sort of thing would be ideal. I believe the fittings are generally 1/8” thread.

[jakethebeast]

Yesh! Foster fittings are ideal for this, so if your actually building something "finished" I'd highly suggets on using them. I just wanted to point out that normal QD fittings do seem to last at higher pressures, but its always risky going over the recommended pressure limit

[Alex345]

If you don’t mind ordering than this sort of thing would be ideal. I believe the fittings are generally 1/8” thread.

It's only 17 dollars, but the shipping is close to 30 for a European like me :p But i like the idea! I could check out some more local online paintball stores to see if they have something similar.

Yesh! Foster fittings are ideal for this, so if your actually building something "finished" I'd highly suggets on using them. I just wanted to point out that normal QD fittings do seem to last at higher pressures, but its always risky going over the recommended pressure limit

I'll check if i still have the right amount of cheap QD fittings lying around to complete it, it would be a waste to spend extra money on it. I'll see if i can find a paintball supply store that could supply me with both the high pressure hose and the Foster fittings. I thought that if the QD on the pilot side failed the cannon would go off on it's own, but i did not think that one through as the solenoid valve would still be in the closed position. This cannon would fire a large projectile and a counterweight of equal mass to eliminate recoil, so if that concept fails i might tear it down completely to build a new cannon. I'm not even sure if the thin duct tape-wrapped PVC barrel can even hold up to that kind of abuse... So polishing will come when the design looks promising

[farcticox1]

Almost finished replacing all my PVC chambers with Stainless Steel piping, never had any problems but was always a bit wary of it, I know it's not rated for any kind of gas pressure and gets brittle with time and cold. A couple I removed I placed on the floor and hit with a hammer (not pressurised) and it was scary how little impact shattered them. Just built the grandson a Nerf gun so PVC was not an option for that.
I was wondering if anyone had any bad experiences with PVC ? maybe I was just lucky

[jackssmirkingrevenge]

I was wondering if anyone had any bad experiences with PVC ? maybe I was just lucky

PVC hybrid explosion

PVC pneumatic failure

[hectmarr]

Almost finished replacing all my PVC chambers with Stainless Steel piping, never had any problems but was always a bit wary of it, I know it's not rated for any kind of gas pressure and gets brittle with time and cold. A couple I removed I placed on the floor and hit with a hammer (not pressurised) and it was scary how little impact shattered them. Just built the grandson a Nerf gun so PVC was not an option for that.
I was wondering if anyone had any bad experiences with PVC ? maybe I was just lucky

Good decision, after seeing what Jack published below .... Ami exploited me a PET plate the material of the bottles of soda, from 40 cm3 to 1.5 or 2 bar approximately and the noise left me with strong pain of head for a whole day ... a total danger. That's why I have a deep respect for what gathers inside more than 5 bar ...