My toilet/sink supply lines provide 1/2" FIP connections behind the drywall, so the original plumbing used 1/2" brass nipples (MIP <-> MIP) to connect the angle stops. I don't like this arrangement, because when I have to replace an angle stop I'll probably have a hard time gripping the nipple without either 1) scratching the crap out of it; or 2) unintentionally unscrewing it from the wall.

My workaround is to build my own nipples by soldering two MIP fittings onto a short copper pipe. The MIP fittings have a nut which makes it easy to hold the nipple steady when changing the angle stop.

Is this a foolish risk to take? Or is it a sensible idea

(Also, I'm a total newbie to soldering pipes; I can inspect the joint from both sides to see if it "looks" sealed, but it could be faulty due to poor workmanship.)

the brass nipple is a thicker/stronger pipe then the copper+fittings you put together.

also with a nipple you can slide on an appropriate size escutcheon when you change out the valve by sliding on a new one when you change valves. With the setup you have the male adapter is larger in diameter so the only option there is a split cover.

The only real thing wrong with it not that it wrong it is just not pleasant to look at
Cut the female lug out and solder on an elbow and stub out, then you sweat and unsweat and style and color valve you would like and it will look pleasing to sums point

Plumbing does not have to look ugly nor should it

the 90 behind the wall appears to be a well secured dropped ear fitting.
you don't have to worry about damaging it in the future.
use a little longer 1/2 brass chrome plated nipple because the flexible connector will make up for any mis-alignment.

ditto packy

nipple(s) should have been chrome plated ORIGINALLY

then you can use a standard slip on escutcheon


[youtu.be]

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

> the 90 behind the wall appears to be a well secured dropped ear fitting.
> you don't have to worry about damaging it in the future.

Right. Not worried about damaging the drop ear. But I am worried about being able to unscrew the angle stop valve when it needs replacement a few years down the line. It's easy to get a good grip on my hex male fitting, hard to get a good grip on a standard brass nipple. Why don't they put some sort of "ribs" on them (or can I buy one that does)?

> The only real thing wrong with it not that it wrong it is just not pleasant to look at

True, but this will be hard to see because it's hidden behind the toilet.

Also, there will be more ugly piping in the vicinity because I'm installing a splitter and water filter for a bidet.

You should have used a male adapter and short stub of copper into the D.E. elbow. Then you could have used a conventional 1/2" compression connection valve. Very easy to replace next time.

I went for the MIP because sometimes inexperienced people (such as myself) have trouble getting the compression torque just right, and if you overtighten it you might deform the pipe and need to cut it. To allow for that possibility I'd probably want to make the pipe a bit longer.

Do you find compression to be less error-prone / leaky then a threaded fitting? Or just prettier?

FWIW, when my expensive licensed plumber did my other house he used compression fittings on the angle stops. But he also used the cheap plastic Brasscraft G2 units from HD, so I'm not sure how much I want to follow his lead...

a 6" pipe wrench grabs the nipple just fine w/o any damage or 'slippage'


[th.bing.com]

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

Compression is easier in terms of getting the stop to orient the way you want to. Yes you can overtightened and strangle the tubing but you can over tighten the threaded joint also. Say you threat on the hot and cold stops and you feel they are tight enough, but that puts the stops at 3'O' clock and 6'O'clock, do you then give them another 270 and 180 degree turn to make them orient up because otherwise your faucet hoses may need to bend or loop to align. So you might end up overtightened. A compression joint does not have this issue since you can rotate the stop to the desire position then tighten.

> Compression is easier in terms of getting the stop to orient the way you want to

True. On this fixture, though, there was already a lot of friction for some reason. I had to go 2 full turns past hand-tight before it passed a 30psi air pressure test.

(I did run the air pressure test before the Tru-Blu was fully cured, so maybe I overtightened after all...)

it SHOULD go 2 (or more) turns past hand tight


1/2" NPT theoretically should go 7 turns total as there are exactly 7 threads in the female fitting and you want full engagement BUT NOT MORE else a wedging open effect

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

IN my 65+ years I NEVER counted the turns when I assembled threaded joints. I turned them until I thought they were tight enough.

in the early 60's i did a 4 year apprentiship at the boston navy yard as a pipefitter. we were never taught to count threads. we were taught to use the right length wrench for the size pipe we were working on.

Correct, even if you had to put a 4'piece of pipe on the wrench.

I bet packy doesn't have room to swing a 4' wrench in a nuclear submarine.

"inexperienced people (such as myself) have trouble getting the compression torque just right"
Bernabeu has a recent post about this (title "NPT Threads", worth a read.
Soldering joints properly is not trivial, there are some techniques to ensure you get the solder to flow throughout the entire joint and properly adhere:
(1) make sure you have no water anywhere in sight. Key thing is temperature, and any water, even a drop, keeps things cool.
(2) make sure joint surfaces are CLEAN, and SHINY.
(3) make sure you use soldering flux (and non-lead solder for plumbing)
(4) when heating a joint with a torch, there is the outer (female) part and the inner (male) part. Hold the torch on the outer female part, on ONE side only. Then hold your solder touching the inner MALE part, in the opposite side. The heat will flow to the inner opposite side last, so when it is hot enough to melt your solder, you are guaranteed that ALL of the metal in the joint is sufficiently hot to melt and adhere to the solder. At the point, the solder should flow quickly and easily throughout the joint.



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