pipe threads- use pipe compound or teflon tape ?

[rfuerst911sc]

Going to be installing a shower valve and all plumbing is new. Is there a preference between using teflon tape vs. pipe compound ? I want to try and do this once .

[redstrosekNic]

I like the tape. Just make sure to wrap the tape in the proper direction on the fitting.

[bell]

Personally I love teflon paste......has never failed or came off when threading together:-)

[pete3799]

This is what i use......works great.

[1990C4S]

For home: either. For engines and hydraulics: paste only.

Teflon tape is bad for clogging little oil passages. It is banned from lots of industrial installations for that reason.

[schamp]

You can use both. I was told to use both on installing galvanized pipe for the compressor air lines.

[Zeke]

For some reason I prefer the tape on non ferrous and the pipe compound on ferrous.

[onewhippedpuppy]

You can't screw up the paste.

[Baz]

Originally Posted by pete3799

This is what i use......works great.

+1

This is all I ever use....Permatex is the right stuff (do not use Oatey!)

PS - I don't use tape at all - and have had no issues.

[75'930cab]

Professional plumbers will use teflon tape and teflon paste too. Pretty much guaranteed not to leak.

[sammyg2]

DuPont does not allow teflon tape to be used on their machines that make teflon tape.
It's also banned in the plant where I work.
If teflon tape will do the job, teflon paste will do it as good or better.

BTW be really careful if you ever have to use a torch around PTFE. When it burns one of the byproducts is hydrofluoric acid AKA alien acid. Eats through glass and 316 stainless.

[NY65912]

Teflon tape should be applied no more than a few wraps. Make sure to keep the tape away from the first thread so itdoes not get into the line. We use teflon tape and paste (in the fitting when installing fire sprinkler systems (yes, we test and flush).

The biggest PITA is plastic pipe. PVC requires a special compound not teflon tape.

We use LACO brand compounds.

[rfuerst911sc]

I used pipe dope on all the joints today. Have not applied water pressure yet but between the amount of goop and the torque applied I'm hoping no leaks.

[944Larry]

Originally Posted by pete3799

This is what i use......works great.

Me too! Works great.

[SXSMAN]

For home and shop it's Gasola ( Fuel Transfer Pumps, Gas Station Supplies, Fuel Nozzles, Transfer Tanks | John M Ellsworth Co Inc )

Never had a failure.

[cbush]

Originally Posted by 75'930cab

Professional plumbers will use teflon tape and teflon paste too. Pretty much guaranteed not to leak.

This is what I do- I figure if one works good, two will work better. Haven't had a leak doing this.

[azasadny]

I use the paste and it's always worked well for me... I always manage to drop the roll of teflon tape and it get unrolled and tangled, I hate the stuff...

[sammyg2]

Supposedly, with tape you use 1 1/2 wraps for new threads that have never been tightened and 2 1/2 wraps for re-making used threads.

for natural gas you need to use special yellow gas tape, not the standard white stuff. Not sure why, something to do with code.

I wouldn't use either for natural gas but that's just me.

The real problem with tape is that even if it's assembled correctly (wrap direction of threads, stay back at least one thread) as soon as you take it apart you'll have slivers of tape stuck in there that are a bugger to get out.

Put it back together and those slivers tends to go to other places, often where you don't want them.

[Willem Fick]

Originally Posted by sammyg2

for natural gas you need to use special yellow gas tape, not the standard white stuff. Not sure why, something to do with code.

I used to run a plant that manufactured PTFE tape. As part of the process raw teflon powder is mixed with pharma grade liquid paraffin which turns the powder into a pliable clay (now you know why teflon makes a poor engine oil additive). This paraffin is removed at the end of the manufacturing process through forced evaporation at high temperature.

Obviously in the interests of efficiency and productivity only so much of the paraffin can be allowed to evaporate. This residue could create a potentially dangerous situation specifically when the tape used on oxygen lines and cylinders as the residual paraffin can react explosively in the presence of oxygen. I can't imagine that this would be the same for natural gas, but I suspect the code is an extension of that applied to oxygen.

For this reason the yellow (oxygen) grade of tape is generally heated to a slightly higher temperature during the evaporation phase of the production process so as to ensure more complete evaporation. In addition to this it is also sent for batch analysis to certify that it has a paraffin content that does not exceed a specific level. These records have to be kept for audit purposes.

As a matter of interest, the paraffin content is actually so extremely low after the regular evaporation process, that even white grade PTFE tape is safe to use on oxygen equipment - the expense of having it certified is simply not justified.

[plumb4u2]

above statements are correct, as a professional plumber I use both, period. The tape is the seal the dope is more to lubricate the threads so they seat properly

only some situations require one or the other for example some plastic (PVC) dope will cause failure over time