PTFE, silicon or nothing on sea cock threads

[Little Dorrit]

What is the recommended way to seal a stainless threaded elbow to the ball valve (and the ball valve to the skin fitting). Are these likely to be self sealing or can I uses PTFE tape or similar. PTFE tape would help ensure the fittings align in the right place so that would be my preference. If I use silicone to seal the threads where would this go? I assume a small amount on the threads? What's best practice?

 

[pvb]

Loctite 55 pipe sealing cord is popular with many people.

 

[lpdsn]

I usually use PTFE tape. However this year I rushed one - my helper with the step wrench had to leave - and I ended up with a small leak, fortunately inboard of the ball valve. I fixed it when back in the water and decided to try Sikaflex on the threads when re-assembling and that worked well.

PTFE tape is less of a sealant and more to make it easier to take things apart several years down the road.

 

[Little Dorrit]

Loctite 55 pipe sealing cord is popular with many people.

Thank you for the suggestion. I have now identified a source from eBay Loctite-55-Pipe-Sealing-Cord-Size-50-m-roll but will await any other suggestions

 

[cmedsailor]

I used Loctite 577 on the threads last year when I replaced the seacocks.

 

[philwebb]

Try using Loctite 55 thread sealing tape. From plumbers merchants or Screwfix. Superior to PTFE tape in that you can change the alignment without it leaking. If you insist on a silicone sealant you will find Fernox LSX is good and seals quickly, although you might find it difficult to dismantle. Loctite 55 for best results though.

 

[sailaboutvic]

Loctite 55 pipe sealing cord is popular with many people.

I used it on 8 sea cock last year , had to reinline a few so the handle would be free to move.
I also used it on all my water maker fitting, works a treat,

 

[SPWiddy]

+1 for loctite 55.

 

[Plevier]

I used Loctite 577 on the threads last year when I replaced the seacocks.

+1, good stuff.

 

[Malish]

Liquid PTFE for example:

https://www.screwfix.com/p/flomasta-ptfe-liquid-50g/5321j#_=p

Works a treat

 

[ghostlymoron]

"PTFE tape is less of a sealant and more to make it easier to take things apart several years down the road.
Read more at http://www.ybw.com/forums/showthread.php?492718-PTFE-silicon-or-nothing-on-sea-cock-threads#db4QTTpvFLFEB82i.99"
Not so, PTFE both seals the minute gaps which exist in metal to metal joints and makes it easier to tighten or loosen joints. I always use it and so do the majority of plumbers I would imagine.