My First Pneumatic Cannon Fail

[ew23]

Well never mind this is getting scraped asap lol

[clemsonguy1125]

Looks cool but unfortuanatly you used dwv which isn't pressure rated and has short socket depths socrüe fittings could blow off

[ew23]

Alright thanks I will scrap this one and build a new one.

[clemsonguy1125]

You can salvage the sprinkler valve and a few other parts probably

[ew23]

I'll try to. Live and learn

[clemsonguy1125]

Yeah, one of my first pneumatics had dwv too

[Gun Freak]

That hose is making the gun like impossible to fire dude. Shorten it!

[ew23]

Thanks I will do that.

[ew23]

Ok this is probably a silly question but oh well. Where do you get the right fittings? I'm guessing you just have to look harder because the ones I used were right by the pipe.

[clemsonguy1125]

Also I'd put the valve on the top so you won't lose power

[Gun Freak]

Well just look for the ones that say Sch 40 on then and don't have the fancy bevels and all on them like DWV. Or just ask a person working there.

[clemsonguy1125]

Wee at most hardware stores 2 in and under are pressure rated just loo for nsfpw above 2 inch most are dwv

[MrCrowley]

Well just look for the ones that say Sch 40 on then and don't have the fancy bevels and all on them like DWV. Or just ask a person working there

*Facepalm*

I hate this internet myth that Sch 40 is pressure rated. You can get Sch 40 DWV fittings that look like pressure rated fittings, so that isn't very good advice.

ew23,
Read this.

Also, please don't post twice in a row. Either edit your previous post or wait for someone else to reply, but don't post two messages in the same thread one after the next. Thanks

Apart from that, the others are right about the dangerous DWV fittings and unneecessary hose length. A sprinkler valve works like a piston valve. The blowgun vents out all the air behind the valve so that it can open, more air behind the valve (pilot volume, i.e the air inside your hose) means it will take longer to vent which means the valve opens slower, or not at all. You want this area to be as small as possible so the valve opens really fast.

Try attaching the blowgun straight to the sprinkler or a far shorter hose (6" or so).

[Technician1002]

DWV is OK for low pressure. After all it has to contain standing liquid in the low spots and withstand the force of a mass of liquid hitting bends at reasonable speeds.

Use it for tossing eggs.

[MrCrowley]

By the way, the pipe you used is pressure rated. Though, the main concern with any DWV component is always the fitting and not the pipe as the fittings have shallow socket depths.

As Tech said, low pressures are fine. I'm sure they can handle 60PSI without too much problem, some people take them even over 100PSI but it is really up to you what you want to do.