Compression fitting pops out

[JohnWW]

I am a plumbing novice and I am replacing a kitchen faucet.

The supply line coming out of the shutoff valve is 1/2 copper. The end of the pipe is cut square.

I bought a Watts compression fitting, brass, 5/8 OD to 3/8 OD to attach the line coming from the faucet.

The cold water line worked fine.

The hot water line is making me nuts. (I am only dealing with cold water so far, I can't run the water long enough until it gets hot.)

I put the sleeve and nut on the pipe until it bottoms out. I put the insert in the pipe and then attach the other piece and tighten it, but it just pops right off, like it is just not grabbing.

I have made sure the end of the pipe is clean and dry, no oils, tapes, or anything else to reduce friction.

What am I doing wrong?

 

[phishfood]

If you are dealing with copper as you say, you do not need or want the insert. Are you using a brass ring? Are you lubricating the threads just a little bit to make sure it is tightening properly? Are you tightening the nut enough to make the brass ring compress into the copper pipe?

 

[JohnWW]

If you are dealing with copper as you say, you do not need or want the insert. Are you using a brass ring? Are you lubricating the threads just a little bit to make sure it is tightening properly? Are you tightening the nut enough to make the brass ring compress into the copper pipe?

I figured out that I didn't want the insert. I have no idea what I was thinking.

I used two wrenches to tighten that down to the stopping point, and yet I can lift the fitting off the end of the pipe when done.

A friend told me the compression fitting I am using is not preferable. They don't like the ones where the ferule is connected to the nut like this one.

I am away from home for the weekend, but will see what I can figure out on Tuesday.

Thanks for your reply.