SpudFiles

Hey im just wondering about threading a 1/4" brass nipple into a coke bottle lid. will this pop out from pressure? If it would, is there another way i can put it in?

Same question but for 2" PVC. im gonna thread one into there and i dont know if it would pop out.

Thanks in advance

It's fine with any size PVC, just put it through a coupler or fitting so it's double layered and stronger. I'm not sure about Coke bottles.

PET doesn't seem like you could tap it in such a obtuse fashion, but I have no experience in the field and no formulas, so just take that as a guess.
(edit: disregard. I thought you where asking about tapping the neck of the bottle)

That said, you <i>can</i> tap a hole into PVC with the fitting... although it's hard to do and not as good as using a proper pipe tap.

For the PVC question you can always thread those round circular disk shape things over it on the inside...ill try and find a pic of what I mean...
Anyway they're bbrass fitting in the shape of a disk with threads on the inside and they're flat...

Im pretty sure that threading into sch40 pvc will work. Just remember not to go all the way in with the tap, and if you mess up JBweld will seal any leaks. As for a bottle cap i am not sure ,but i have successfully put a rubber schrader vavle in the cap and held it over 100psi.(the bottle blew past 125) Im not sure what your trying to achieve, but rubber schrader valves work well. I personally would thread the cap as best as i could then put a coupler on the other end of the nipple(acts as a nut) and then coat most of that in JBweld.

Fot tapping anything smaller than 1/4" into PVC, I just drill the appropriate sized hole, then pop the nipple or schrader valve into the drill chuck. Then I drill it into the hole, take it out, wrap it with teflon tape, then drill it in again. Has never failed.

"For the PVC question you can always thread those round circular disk shape things over it on the inside...ill try and find a pic of what I mean...
Anyway they're bbrass fitting in the shape of a disk with threads on the inside and they're flat..."
Locknut?

Yup thats the one...Locknut

Bottle caps will form a pressure tight seal up to 50ish psi if you drill a hole and epoxy the hell out of it. You can forget about threading it, the plastic is way too thin to make a difference. I forget what it is but there is a plumbing part that fits dang well over a bottle's threads, I think it might be 3/4" NPS.

I used a steel-nipple-in-bottlecap in the flamethrower from hell, aka 13 consecutive bad ideas, and I'm not gonna go into further details because that's not allowed on the forum but it worked well enough that it didn't rupture or anything, so for light use applications it will work well.

You can do it in a Coke bottle, I have done it. Just thread it in and then put a nut on the back side or some epoxy on it and it will be fine.