Sweating Cu Pipe and Kitchen Sink P-Trap Questions

[KP Texan]

I've followed this forum for awhile now and from things I've learned here and other places around the net I decided to attempt to solder my own water stop valves beneath my kitchen sink. The previous valves weren't doing too well; one of them leaked through the outlet when shut off and the outlet on the other one would not properly seal properly with a stainless braided flexible hose that used an internal brass compression fitting (rather than rubber). These valves were also attached to the copper stub outs using compression fittings. Once those fittings were cut off, it did not leave me much room for error with another compression fitting so that's another reason I decided to try my hand at soldering some new valves on. I purchased a Bernzomatic TS8000 torch with MAPP gas, various copper fittings, some Keeney quarter turn valves, some wire cleaning brushes, and a Lenox kit that included some Sterling flux and solder. Everything seemed to go well with the soldering; I made sure to properly clean all joints inside/out, flux both parts, and heat the joint so that the solder would flow towards the heat while being careful not to overheat (that Mapp gas heats pretty quick!). Here's my question: how long should I carefully watch these joints for signs of leakage? Although I'm pretty handy and have done some welding and soldering, this is my first time to sweat copper pipe so I'm sort of skeptical of the quality. Do these joints typically develop pinhole leaks first or do they catastrophically fail and tend to cause flooding?? It never freezes here so I don't really have to worry about stresses other than standard water pressure.

My other question relates to the configuration of my under sink drain piping. My garbage disposer went out and I purchased a new one. The new disposer had a down turned outlet rather than a straight pipe coming out like the old one. I now have two P-traps; one from the disposer and one from the other sink bowl. Will this pass code? Please see attached pics.

Thanks so much,

Wes

 

[Terry]

All disposers come with a down bend.
I throw those away and run a straight pipe to the tee.
You need to get rid of the second p-trap.

Also, is that a baffle tee?
If not, when the disposer runs, the water is going to go both ways.

What you needed was a disposer kit. it comes with the baffle tee, and the straight pipe.

 

[Sponsor]

 

[Gary Swart]

As far as your soldering is concerned, if you did all the joints as your described, you should be just fine. A joint will not fail if soldering is done properly, it is possible to do a poor job of soldering and the joint may last for a considerable time then fail, but usually a poor joint show up immediately. You should be able to fix the drain situation easily since the is plenty of space to work.

 

[Gardner]

is that a baffle tee?

It looks to my uneducated eye like a centre outlet baffle tee laying on its side.

 

[KP Texan]

So from the copper joints that you have seen fail, do the majority of them start with a slight leak or do they typically just blow out without warning?

That is a plain old T and not a baffle T. I suppose I'll be picking up a disposal installation kit! The issue I have is that the outlet to the disposal is not much higher than the top of the main P-trap. I think I've also got a code issue with the way my P-trap is vertically aligned with my copper drain pipe from the wall. That flexible coupling is allowing an ever so slight bend and the P-trap outlet is actually slightly lower than the copper drain pipe. From my understanding it needs to be the other way around? It might just be an illusion but it seems that way.

Thanks so much for the help,

Wes

 

[Gary Swart]

I have had only one old joint failure and it wasn't my job. The main shut off valve on my supply line blew off after being bumped. It's a long story, but the professional plumbers soldered this on my new supply line but there was a small leak from the meter that prevented a good joint. I did have a failure once when I forgot to flux a tee, but that was instant and from my carelessness rather than just a poor job of soldering. I think you are worrying needlessly.

 

[KP Texan]

Yeah, I tend to worry too much about things like that; I just envision coming home from work one day and seeing water shooting out from the cabinet door under the sink!

Thanks,

Wes

 

[Jadnashua]

Second thing while you are out getting parts...replace that rubber coupling at the wall with either a banded coupling (rubber sleeve with metal to support the pipes) or a Desanko (can't remember the other names). That fitting is only supposed to be used underground (and most places don't allow that small of a pipe underground!).

 

[hj]

joints

I replaced a copper solder tee yesterday, 1 1/2" x 1". When the old one fell on the ground it popped apart. The 1' was inserted less than a QUARTER INCH into the tee, and even that 1/4" joint was done so poorly that a fourth of it did not have solder in the little bit of socket engaged so it was only sealed by the bead of solder at the surface of the joint. The installation was 25 years old, but you could see from the corrosion that it had been leaking for a LONG time. Fortunately it was in a ceiling where nothing could hit it, because even the slightest bump or movement would probably have dislodged the 1" pipe. As for the drain, you have the wrong fittings, such as the all slip tee and the second trap is not technically illegal, but it is also not necessary. A plumber would NOT have cut the compression stops off, and most, such as myself, would NEVER solder new stops on.

 

[KP Texan]

A plumber would NOT have cut the compression stops off, and most, such as myself, would NEVER solder new stops on.

Why is this?

Thanks,

Wes

 

[Kingsotall]

It's best to try to pull the ferules off with either a stop puller or good ole channey locks (you pull on the nut) and then replace with 1/4 turn comp stops. There is a time and place for sweating but not for supply stops.

 

[KP Texan]

The issue I had is that the ferrule had compressed the copper pipe. I've never used a ferrule puller but I'd venture to say that it could not be done without tearing up the end of the copper pipe. Even if you could get the ferrule off, the copper pipe would still be crimped. I took my Dremel and then cut a deep slot in the ferrule and used a screwdriver to pop it off. Then, I was able to use a tubing cutter and remove only the damaged portion of the copper pipe.

My reasoning behind sweating the valve on was because I was led to believe that a sweated connection is of a higher quality than a compression connection. This idea came from the fact that a compression fitting is not allowed in a hidden space but a sweated fitting is, thus a sweated fitting must be more reliable.

Thanks,

Wes

 

[hj]

valve

A sweated valve's JOINT is more reliable and also much more permanent. In most cases I use the old nut and ferrule, but if not I use a puller to remove the old ones. The problem with soldering is that the joint is right next to the wall or cabinet back, especially when there is not enough pipe for a compression valve, so it will be almost impossible to sweat the valve on without at least some charring, which would be objectionable to most customers. Even if the old tubing is deformed, all that is usually necessary is to cut off enough so the deformed portion is inside the valve past the new ferrule.

 

[SewerRatz]

I always preferred the sweat stops myself. But more for selfish reasons. Most homeowners will be brave enough to change a compression stop, but if they see it sweated on, they normally would call a plumber to replace them. As for charring the wall and such a piece of sheet metal such as stove pipe can be used as a shield. You spray some cool gel on the wall and the back of the sheet metal, and all is good.