Plumbing Questions

[BrandonV]

These are probably silly questions (I don't do much plumbing if at all) but I'll preface by saying I have actual OCD and I can get caught up in details way too much. Psychological disorders are a PITA especially when you're an over-analytical engineer.

1. Most quality PTFE sealing tapes say to apply 2-3 wraps. If the tape is 1/2" and I'm applying it to a 3/4" male NPT fitting should I try to apply 2-3 wraps to all the threads or is just applying the tape in the middle sufficient (see photo)? I assume that is where the majority of the sealing is occurring. There is obviously the option to buy 3/4" tape but I don't see that for sale locally. I also fail to see why I'd waste tape like a lot of videos where no thread to thread contact will occur.

2. If I was trying to wrap a larger pipe (e.g. 1") with 1/2" PTFE tape what sort of overlap method should I use? Should I overlap to try to get all sections covered by 2-3 wraps?

3. I am trying to convert 3/8" soft copper tubing to 3/8" polyethylene tubing for an RO system. There are lots of fittings that state they're for 3/8" tubing (obviously designed/marked for copper). Can I swap out the compression ring on one end with one made of Delrin with a brass insert on the polyethylene tubing?

https://imgur.com/8w7rH14

Thanks.

 

[housewolf]

These are probably silly questions (I don't do much plumbing if at all) but I'll preface by saying I have actual OCD and I can get caught up in details way too much. Psychological disorders are a PITA especially when you're an over-analytical engineer.

1. Most quality PTFE sealing tapes say to apply 2-3 wraps. If the tape is 1/2" and I'm applying it to a 3/4" male NPT fitting should I try to apply 2-3 wraps to all the threads or is just applying the tape in the middle sufficient (see photo)? I assume that is where the majority of the sealing is occurring. There is obviously the option to buy 3/4" tape but I don't see that for sale locally. I also fail to see why I'd waste tape like a lot of videos where no thread to thread contact will occur.

2. If I was trying to wrap a larger pipe (e.g. 1") with 1/2" PTFE tape what sort of overlap method should I use? Should I overlap to try to get all sections covered by 2-3 wraps?

3. I am trying to convert 3/8" soft copper tubing to 3/8" polyethylene tubing for an RO system. There are lots of fittings that state they're for 3/8" tubing (obviously designed/marked for copper). Can I swap out the compression ring on one end with one made of Delrin with a brass insert on the polyethylene tubing?

https://imgur.com/8w7rH14

Thanks.

I agree, I think you are overthinking this quite a bit. I’ve had a masters plumbing license since 1990 and never gave it that much thought. I generally start at the end of the pipe working my way up and try to get 6-8 ( I don’t count) wraps around it. If it’s larger pipe, like 1-1/2” or 2”, yeah, it’ll take more wraps. Remember to wrap in the same direction you’d go as if screwing a fitting on. I don’t use a lot of t-tape, but in the case of RO and you are trying to keep it clean, Teflon is probably better than pipe dope.

I see no reason you couldn’t swap the brass ferrule for another material.

 

[Jackfre]

If RT handed, hold the fitting in your left hand with threads laying off to the Rt. Place your Left thumb over the end of the tape at the deepest part of the threads and with your rt hand take the tape out to barely cover the starting thread. Wind it tightly and after 2-3 wraps pull it tight breaking the tape. Just watch out to not put much tape over the starting thread as the threads will cut the tape and you can end up with threads of tape in the pipe. If this really drives you nuts and you do not want to use tape just get some pipe dope and make a mess.

 

[BrandonV]

Thanks all. I think I've just been overthinking the whole thing.

Bad habit I've developed.

 

[racecougar]

The tape application shown in your photo looks perfect.

 

[rlitman]

The tape application shown in your photo looks perfect.

I agree. But that's the thick blue tape, which really only needs 2-3 wraps. The 6-8 wraps answer found above is correct for the thinner white tape.