Help attaching lid to ss stock pot lid

[moons]

Hey guys so i thought i knew what i was doing with this (3 gallon) stock pot still, but i dont when it comes to attaching the column. I tried a 3/4 female and 3/4 male and tightening that down to hell and back but there were to many threads still exposed aka horrible seal and still loose. I thought 3/4 copper pipe is kind small to make a flange so i was wondering if i could cut off some of those threads on the male end so then it would be a tight seal. Thanks guy any help appreciated p.s. pictures help a lot if you have them... thanks!

[myles]

A lot depends on your threads. Usually the female thread is parallel. If your male is tapered it is not intended to fit all the way - resulting in a poor seal onto the lid (but a good seal between the threads).

If the male is parallel also then it is supposed to bottom out against a washer or seal in the base of the female thread. Also some of the male threads do not extend all the way to the flange so you might have to bulk up the wall with some copper washers.

The good news is that if you can get it tight then you can solder it to make it vapour tight. Just don't exxpect to take it apart again.

[myles]

That is a 2" compression tank connector fitted to a stainless stock pot. I hard soldered it so it is never coming off again.

[Dnderhead]

what you want is a balk head fitting,used on boats,tanks etc

[moons]

Ok i think i will look for a parallel thread male and female; would home depot, menards or ace hardware have that type of thread? And would it be ok to wrap the threads in ptfe or teflon? just so that it creates an the best seal possible without solder. Thanks for you help guys!

[Dnderhead]

i just toal ya,,look for balk head fittings..used on boats,and tanks like spray tanks/water tanks etc..

[myles]

There is an alternative moons but it might not be worth it on a 3 gal pot.

You can rivet and solder a copper disc of about 3" or 4" in diameter to your lid and then you attach your vapour path onto that instead. It means that you can permanently fit a short tube onto your lid with simple solder joints and use that as the base for your vapour path.

[mash rookie]

i just toal ya,,look for balk head fittings..used on boats,and tanks like spray tanks/water tanks etc..

OMG You know boats too? I think Dunder is IBM's big blue.

Yes, bulk head fittings are NPS (national pipe straight ) V/S npt. (national pipe taper) They are not easy to find everywhere.

You can trim a little off the male. Use a couple of stainless washers. That would be easier.
MR

[moons]

i just toal ya,,look for balk head fittings..used on boats,and tanks like spray tanks/water tanks etc..

Sorry i missed understood you i thought it was a second way if parallel threads were not available. I will search for a balk head then if its not avabile go with mash rookie's idea with SS washer Thank you guys

[beowoulfe]

That's "BULK HEAD" fittings. Dndrhead had a finger check.

[Dnderhead]

""You can trim a little off the male"""
with tapered thread that wont do any good..
as it does not bottom out..they fit like a cork in a bottle..
.retreading deeper mite,but the easiest way is to fiend a copper/stainless washer. or git/make a different fitting.