I feel like a fool posting this but am going nuts with with a couple of compression fittings on a pedestal sink. I’ve installed hundreds of compression fittings over the years on pedestal sink and toilet supply lines (chrome plated brass tubing) but lately have been having a hell of a time getting the damn things not to seep. At first I thought it was cheapening of materials from my big box so I went to my regular plumbing supplier only to find that he was using the same brand fittings. Tried another supplier with different brand supplies (same brand compression nuts and ferrules) but still have leaks.
Oh yeah, they leak between the compression nut/ferrule and the supply line.
Has anyone else run into this problem and if so, how did you solve it?
Thanks,
DGW
Replies
Wonder if you have some very extra spcial high quality guaranteed supply lines that are not an SAE type size, but rather some sort of made in China almost size?
Kinda like those tennis shoes they make, got three or four different sizes inside, but not my size?
Joe H
This is one reason why I prefer to use NoBurst hose when possible.
If you've done this a lot it's probably not news, but one trick to a leak-proof joint is to not jam the inner pipe all the way into the fitting, but to leave it with about 1/8-1/16" headroom. This way, when you tighten the compression nut against the ferrule, causing the pipe to "extrude" slightly, it has a place to go.
Are you using metal supply tubes? Use PEX supply tubes with the delrin (plastic) ferrules.
use stainless steel flex lines , ridgid pipe went out with the ark
I almost agree.
But when the toilet or lav is exposed a rigid chrome line with nice sweeping bends always looks better than a loop of braided.No Veterans = No USA-----Bumper Sticker
a plumber friend told me
tighten while its leaking at first, til it stops leaking then just a mite more
Some can be real touchy.
I always use dope on the ferrul, & inside the recieving end of the joint.No Veterans = No USA-----Bumper Sticker
"I always use dope on the ferrul, & inside the recieving end of the joint."Do you think that the dope does any sealing on a compression fitting or does it help by lubricating the parts as you tighten it up so that more force is on seating the parts rather than friction?
pipe dope lubrcates and seals. that is why I use teflon tape on a leaker
sometimes. You may be better off just replacing with,new/undamaged, your choice of materials.
larry
lil of both actually.
Thick pipe dope will help fill in tiny imperfections of the fittings.
Not to really argue with the other guy, but I have seen water leak right through the layers of teflon tape when used on a ferrul.
Granted it was an 1.5" brass ferrul on a trap arm, but it still leaked.No Veterans = No USA-----Bumper Sticker
it's the ferrel seat on the valve... sounds like something is out of round....
metal or plastic ferrel???
put a light coating of pipe dope on everything before you put it together..
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
I'd love to use the braided flex lines but the supplies come up from the floor in a period bathroom and are in plain sight. I've got to get out my micrometer and check the actual OD of the supply line. FWIW the ferrules are brass.
Thanks again for all the comments,
DGW
check for out of roundness,,,
the ferrels sitting at a slight kant...
if you over tighten they will leak...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!<!----><!---->
Forget the primal scream, just ROAR!!!
Look at the adapter or stop valve that this connects to.
The "seat" for the ferrule might be bad.
I've never put anything on the ferrule, was taught not to. I do use teflon tape on the nut, but was told that it was like belt and suspenders...
I plan to put a little pipe dope on the ferrule and see what happens. FWIW the supply, nut and ferrule are Watts, the valves are BrassCraft.
DGW
If you have good materials, on-spec and properly manufactured, properly installed without any misalignment etc., no dope or tape should be required on a compression fitting.
Putting dope on the threads between the nut and fitting body will act as a lubricant, but won't seal anything- that's not the sealing surface. Plumber's grease or antiseize compound will do a better job for that purpose. Putting a little dope on the seal surface between the ferrule and the fitting body will help plug any minute imperfections in the joint, but it will probably just be a leak waiting to happen later. Teflon tape is for taper threaded joints, period- it doesn't belong anywhere on a compression fitting.
The most common problems with compression fittings in my experience are axial scratches on the tubing, ferrules swaged too close to the end of the tube (because somebody didn't bottom out the tubing in the fitting body before they swaged it), and over-tightening. If the tubing's scratched enough that you can feel the scratch with your thumbnail, that's too much.
Make sure whatever is put on the threads is edible - or at least not toxic. I don't think the Anti/Never-Seize qualifies on either count.
But that stuff is SUPER AWESOME for any other metal to metal threaded application. People don't use it enough.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Good point Paul. You don't want to be getting anti-seize on any of the wetted parts! But of course the nut and body of the compression fitting isn't a wetted part. If you don't go nuts or do a messy job of it, anti-seize will be fine. Of course, ordinary plumber's grease will do the job too.