Ever see this?

[Octopus]

I had a pipe fitter adding butterfly valves on CW hydronic system, The pipe fitter used Teflon tape and Teflon dope and it still leaked it seemed to bead right out of the dope, He had them tight and clean what gives I am guessing the pipe is threaded too far back and it's bottomed out? Some real thick pipe dope/gasket maker fixed it but next time I would rather weld them up after all he used Victaulic after the nipples. This happened on all 8 fittings.

[ACRDave]

did you back these fittings out completely and check the threads? i had a die set foul up on me once and didnt catch it untill about my 8th thread. ( you get zoned out with a hand threader! ) they could also be cut too deep as opposed to fouled up. giving the water a place to go.

[prorefco]

Since when is teflon tape supposed to be used along with dope?? I started seeing this about 20 years ago in the northeast. This contradicts what the union taught us. I have found that when using tape with dope it's not uncommon to have leaks....

[flange]

f its going in vic, why not use vic flanges?

[Octopus]

f its going in vic, why not use vic flanges?

Exactly but this was the pipe fitters job to figure out. I had not seen the job untill it was too late.

[C-Jac486]

Since when is teflon tape supposed to be used along with dope?? I started seeing this about 20 years ago in the northeast. This contradicts what the union taught us. I have found that when using tape with dope it's not uncommon to have leaks....

I have to agree... sometimes too much dope is just as bad as no dope at all.... we have "Fitters" at my work making "dope sandwiches" Blue pipe dope. teflon, and more blue pipe dope..... I just laugh and pull out my PST (loctite 567)

[prorefco]

I have tried lots of different kinds of dope but I always came back to good old rectorseal #5 for most applications. All the others leaked at one time or another, either right away or within a year after application.

I also have seen lots and lots of untrained fitters out there who have been working in the trade for decades... And when you attempt to correct their errors, they go off on you... Go figure.....

[C-Jac486]

I have tried lots of different kinds of dope but I always came back to good old rectorseal #5 for most applications. All the others leaked at one time or another, either right away or within a year after application.

I also have seen lots and lots of untrained fitters out there who have been working in the trade for decades... And when you attempt to correct their errors, they go off on you... Go figure.....

Yeah I know what your talking about... they look at you like your some kind of idiot.... I use the rectorseal 5 on gas piping because it contains no teflon.

[stanbyyourword]

i was gonna say rectorseal as well fridge side and plumbing, never had better results , that liquid teflon stuf is junk stan

[Paul Bee]

For some applications rectorseal #2 I use #5 for everything else. I know it is old school but if I really don't want a leak and it is not potable water I use Permatex form a gasket #2 non hardening.

[hvacplumb]

I am a union pipefitter and plumber and I have put together miles of screw pipe and I will always teflon first and then put a little dope on.

[C-Jac486]

I am a union pipefitter and plumber and I have put together miles of screw pipe and I will always teflon first and then put a little dope on.

What local are you out of? I'm a Union Fitter too, I don't see the need for teflon and dope. Some guys, I see using teflon, put too much on causing the teflon to just push up the threads..... Do you use teflon on your gas piping?

[Jettinvr6sc]

rope it and dope it

[Randy S.]

Have the electricians been using the pipe threader again?

[skoonen]

Usually on the larger threaded pipe we use quick wick or lamp wick, whatever ya want to call it, comes in a ball from the plumbing supply house.

[cannedheat]

i'm also a union fitter, local 597. when threading pipe theres a rule of thumb to check your threads after you thread your first piece by hand tightening a fitting on the end of your pipe, to theck thread depth. if done correctly it will not leak. remember teflon tape or dope is for ease and protection of the threads not to stop leaks. i also use teflon 1st then some dope on 1-1/4 or larger dia. for ease of assembly. anything smaller dope or tape seems to work fine. good luck

[toptech]

Steam or water I use Permabond. A little expensive but it dont leak.
Dam Chinese flanges

[mtfallsmikey]

Back in the day.....A pipe dope called John Sunshine, made in an era when lead was still added to pipe dope.....

Mostly use R-Seal #5 now.

[hvacker]

I'm sure some will remember from apprentice school that pipe dope is not a sealer but a lubricant. Correctly made pipe threads are tapered and with a lube will seal themselves.
Any pipe dope will work on good threads. From white lead and linseed oil to what's available today.
I'd suspect the pipe dies were adjusted wrong. You should be able to turn a fitting 3 revolutions by hand before getting tight.
The oddest thing I saw a fitter do was use STP, the oil additive, on an allumium valve boss. It was screwed all the way until it ran out of threads. I still don't know why the boss didn't bust.

[Peztoy]

I've seen old school pipefitters use pipe dope and tape. Some rare times it would leak. He'd then say start the pumps and come back tomorrow, it'll be fine. Sure enough leak was gone. He'd say it just needed a little dirt to seal the joint.

Flange isn't cranked is it?