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When drilling and tapping PVC...
Posted: Mon Jul 31, 2006 2:45 pm
by Kris.Is.Awesome
Do I want to drill and tap through just the PVC tube, or go through the tube, and a fitting aswell?
Posted: Mon Jul 31, 2006 2:53 pm
by Spyider
when i have to screw stuff into my pipes i just drill a hole that is a little smaller than what im inserting then i just screw it into it and it makes its own threds then i take it out and out some "tape" on it then reinsert it. and that usually sealls it tight but if i rly need more i just put some apoxey.
Posted: Mon Jul 31, 2006 2:57 pm
by Kris.Is.Awesome
I know how to drill and tap, I just need to know if I should put it through a fitting- maybe it's stronger.
Can I mount it like this? Is that fitting strong enough to mount it on the 'slant'? Or should I mount it on the flat part- or maybe just the tube?
It's one of theese fittings- I wanna put it on the slant.

Posted: Mon Jul 31, 2006 3:14 pm
by LucyInTheSky
Mount it so it goes through two layer of PVC where the fitting and Pipe overlap.
Posted: Mon Jul 31, 2006 3:15 pm
by Kris.Is.Awesome
LucyInTheSky wrote:Mount it so it goes through two layer of PVC where the fitting and Pipe overlap.
Okay- thanks. Will do.
Posted: Mon Jul 31, 2006 5:48 pm
by mark.f
That looks like a DWV reducing coupling. Not safe for a pneumatic at all...
Posted: Mon Jul 31, 2006 5:57 pm
by Kris.Is.Awesome
markfh11q wrote:That looks like a DWV reducing coupling. Not safe for a pneumatic at all...
That picture was to illustrate the general coupling I used- Are you saying it's a bad Idea?
Posted: Mon Jul 31, 2006 6:49 pm
by Shrimphead
Check to see if the fitting says "NSF-pw" on it. If it doesn't than it means that it's not a pressure rated fitting.
Posted: Mon Jul 31, 2006 6:59 pm
by mark.f
Look also for ASTM 2466.
Posted: Sat Aug 05, 2006 11:47 pm
by iamquaker
so it would not be wise to just tap a hole in the 2" pvc and screw in a pressure gauge if its only going thru one layer of pvc?
would this weaken the pvc and make it rupture where you drilled it?
Posted: Sun Aug 06, 2006 12:17 am
by CS
Mer... The whole reason why it is recommended that you tap threw two layers of PVC is so that the component being "tapped" into there has more material to "grip" on.
Im not completly sure on this, but if I recall correctly reducing/increasing couplings are a thing of the "non-pressure rated" realm, regardless of manufactuer. Ive used them in pneumatics up to 125PSI (thats as high as my compressor goes). I wouldnt scrap your whole gun over such a fitting, but for futures safety Id recommend pressure rated bushings in future builds.
Posted: Sun Aug 06, 2006 1:06 am
by pyrogeek
Going through 2 layers would be best. And I don't care what other people say, use a drill and tap to cut your threads. You can buy taps seperately, and they are only like $3 or $4 each, so they aren't that expensive. And if it's something like a 1/4 NPT tap, it will get plenty of use to justify that expense.
And by the way, ball valves don't have that good of performance. Sprinkler vavles > ball valves.
Posted: Sun Aug 06, 2006 2:42 am
by LucyInTheSky
and QEV > sprinkler valves
Posted: Fri Oct 20, 2006 9:45 pm
by Flying_Salt
And just to be safe if you wanna, do what I do and put a bit of caulk on there. it helps seal it off.
Posted: Thu Nov 02, 2006 6:44 pm
by jon2680
you could also use a snap tee.