adding o-rings to threaded fittings?

[JDP12]

As much fun as sealing threads with teflon tape, testing for leaks, and then resealing it again with tape and retesting for leaks is, On the gun i'm working on i have to disassemble certain things very frequently and retaping the threads each time gets super annoying. I've seen commercial fittings (usually for kitchen/bath fixtures) with o-rings on the threads, and I'm wondering if this is duplicable by the home spudgunner.. and if it is, why don't more people do it? and if ya do it, whats the best way to do it? It doesn't seem like you can just slap an o-ring on the threads anywhere you want.

[DerpWithAGun]

Yes it is very possible just tried it now. It only works on some parts though. You don't exactly put the O-ring on the thread itself but you put the O-ring on a female piece at the end of the thread. My 1/2" ball valve has 1/2" female threads but the actual part where the ball valve opens is only 10mm in diameter. This means there is a flat space at the bottom where the female thread ends so I pushed a 1/2" O-ring down there all way to the bottom and then threaded my 1/2" connecter to the valve as tight as I can. It presses onto the O-ring and now is 100% air tight.

EDIT: Oh, and people don't use O-rings often because they are expensive if you buy them from hardware stores. It's like $2 for a pack of 4 O-rings where I live. I buy my O-rings from a junk shop. $2.50 and I get a huge pack of assorted. all the way from 9.5mm )-rings to 24.5mm O-rings, get 3 - 8 pieces of each O-ring.

[warhead052]

Its better to use O-rings with straight threads, or at least that is what I have found. Other wise I haven't found a way to do it without leaving wrench marks from tightening it far enough to seal against the O-ring.

[Gippeto]

Check with your local hydraulics supplier (farm equipment etc.)...they'll have hydraulic fittings that are o-ring sealed....and pressure rated.

[mark.f]

Compression fittings could be used. Delrin olives are sold at most hardware stores and will work for many disassemblies.

Otherwise, the fittings you see on most sinks and water lines are the same thread as compression fittings and have a gasket in the nut. I used one on Thorondor precisely for the reason you stated, I needed to be able to take it apart easily without having to reseal things with teflon tape.

[JDP12]

ah ok i gotcha now, you put the o-ring in the female part as opposed to on the male part. Thanks! I may have to try that now.

[jackssmirkingrevenge]

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