Compression Fitting

[Bertman48]

I read an article that recommended putting pipe joint compound all over the ferrule when installing a compression shut-off valve. Is that a good recommendation?

Also, does the supply line copper tubing have to be inserted all of the way into the shut-off valve or can it be partially inserted?

Thanks,
Bertman48

[Bob NH]

The copper tubing should be inserted all the way to ensure proper mechanical alignment and resistance against bending. Otherwise, it can bend and the ferrule won't always seal properly and permanently.

The pipe dope contans a little oil that will cut down the friction between the nut and the ferrule. It usually isn't going to hurt if you don't get carried away. On the other hand, it is not a magic potion to fix a misaligned or overtorqued fitting.

[plumber1]

If you want to use something, a little grease could help........

[jimbo]

Plumbers grease, a little 3-in-one oil, or some dope are all good to prevent future galling. I do like to use teflon paste. I would no use some of the "stiffer" non-teflon pastes, as some of then actually take a set over time.

[Terry]

Sleeve puller

At the most, I use a light spray oil on the threads.
Most of the time, I don't even do that.

I replace compression stops all the time.
Some use more than that, but I never have.

Compression fittings work well.
They are one of the fastest methods around, and they still allow for replacement with a sleeve puller, which I have in the tool box.