Stopping pesky leaks on new compression fittings?

[SwitchTheElectricsOff]

Morning everyone

I hope the experts can help me out with an almost a routine issue I have - Compression fittings leaks

This is what I do:

• Insert the copper pipe into the compression fitting
• Mark a line where the fitting comes up to
• Pop the bolt and olive on
• Put a dab of LS-X on the copper pipe to the line
• Insert the pipe into the compression fitting
• Bring the olive to the join and wrap ptfe tape twice around the olive
• Pop some ptfe tape on the screw for lubrication
• Hand tighten the bolt, and mark with a line across the bolt and pipe
• Grab my wrenches, one on the fitting, the other on the bolt and tighten about 1/4 of the way (sometimes it's half, other times it's a full turn)
• Hope for the best

What exactly am I doing wrong? It's pretty hit and miss when I do it, driving me crazy

Thankyou for any advice!

 

[Tigercubrider]

I have never added PTFE to an olive, although I have to screw threads.
I just think you're not tightening it up enough

 

[SwitchTheElectricsOff]

I'm quite nervous about tightening, how much of a turn should I give it? Everything I've read and watched implies 1/4 of a turn, but in the real world, what type of tension should I be feeling for? I'm doing it up as tight as I feel comfortable with, but as you say, I might need to give it a bit more welly!

I have never added PTFE to an olive, although I have to screw threads.
I just think you're not tightening it up enough

 

[just pumps]

Nut & olive on pipe
Insert pipe to fitting
Tighten nut

Shouldn`t need any sealant or tape on new quality parts.

 

[oldbuffer]

1. As you say, there is a strong general implication of "hand tight plus 1/4 turn". However, one persons hand tight is another's loose, so its pretty meaningless.
2. As stated above with good quality fittings, you should not need anything at all to make a water tight seal.
3. I think its pretty much an experience issue. You get a feel for just how tight it needs to be when you've done a few.
4. Why not try fitting a pipe to a (valved) mains water source, then putting a compression fitting on and tightening up gradually until there is no leak. Might give you a feel to start working on.

 

[just pumps]

As above re experience, remember as an apprentice I totally mullered a compression fitting on 8mm copper pipe even using the correct spanners.

 

[Madrab]

No PTFE on threads needed ... ever!!

A new compression fitting should need absolutely nothing added. It may need a couple of turns of tape around the olive (where the seal is made) if it's brass and your not experienced as to how tight it needs to be. Copper olives should need nothing. Tighten to squeaking point is usually my gauge.

Only other thing I would do is clean the copper, if it's old pipe, before it all gets assembled and tightened.

 

[SwitchTheElectricsOff]

Ah, I usually goto the big W merchant and use their own brand, what other should I be looking at?

Nut & olive on pipe
Insert pipe to fitting
Tighten nut

Shouldn`t need any sealant or tape on new quality parts.

 

[SwitchTheElectricsOff]

Tighten to Squeaking point I definitely don't do then!

No PTFE on threads needed ... ever!!

A new compression fitting should need absolutely nothing added. It may need a couple of turns of tape around the olive (where the seal is made) if it's brass and your not experienced as to how tight it needs to be. Copper olives should need nothing. Tighten to squeaking point is usually my gauge.

Only other thing I would do is clean the copper, if it's old pipe, before it all gets assembled and tightened.

 

[SwitchTheElectricsOff]

Thanks for that, I noted from Madrab squeaking point, that's what I never do

The last handful of compressions have been perfect, and I thought I had over tightened them due to all the warnings I read about, so working out what I'm doing wrong, and it seems it's all in the wrist action

1. As you say, there is a strong general implication of "hand tight plus 1/4 turn". However, one persons hand tight is another's loose, so its pretty meaningless.
2. As stated above with good quality fittings, you should not need anything at all to make a water tight seal.
3. I think its pretty much an experience issue. You get a feel for just how tight it needs to be when you've done a few.
4. Why not try fitting a pipe to a (valved) mains water source, then putting a compression fitting on and tightening up gradually until there is no leak. Might give you a feel to start working on.

 

[just pumps]

Use an old fitting and pipe with a new copper olive and tighten until you think it is enough then dismantle and take a look at the olive & pipe. Then over tighten it in your mind, if the pipe has deformed then yep that`s too tight. I prefer copper to brass olives.

 

[durhamplumber]

I have never used ptfe or any other sealant on a new compression fitting.In 35 years.

 

[ianmcd]

if you want to use PTFE, tighten the fitting until the olive bites into the pipe , undo the fitting and then wrap the olive with a small amount of PTFE and then retighten, have only had to do this a few times if the joint is weeping, definately never put PTFE on before the olive has compressed

 

[SwitchTheElectricsOff]

I didn't even think of that! I'll give it a go tomorrow (currently tiling our bathroom - jack of all trades...)

Use an old fitting and pipe with a new copper olive and tighten until you think it is enough then dismantle and take a look at the olive & pipe. Then over tighten it in your mind, if the pipe has deformed then yep that`s too tight. I prefer copper to brass olives.

 

[SwitchTheElectricsOff]

Can I ask a dumb newbie question, why is that? as in, all the videos I've seen always mention the tape?

I have never used ptfe or any other sealant on a new compression fitting.In 35 years.