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taydin
08-06-2011, 03:16 PM
I am not familiar with plastic pipe terminology, so I hope you will understand when I describe the problem ...

I noticed a water leak from the wall. The leak was coming from the pipe thread that is embedded in the wall. Closely examining the thread, I noticed that there is a crack in it. I am not able to take a picture at the moment, so I just drew the situation roughly using my cad program.

All pipes are plastic. Both ends of the 1/2" pipe on the top are embedded in the concrete wall. The 90 degree piece at the bottom has a metal thread and that thread is cracked. I need to change that, but if I cut it off, the short piece of pipe that holds the tee to the 90 degree piece will still be left in the tee, so I can't weld the replacement piece into the tee. I would have to enlarge the hole using a drill that has a 90 degree mandrel, but then pieces of plastic can get into the pipe, and I don't have such a special drill. How would you fix this?

http://www.taydin.org/web/tesisat_ariza/tesisat.jpg

Evan
08-06-2011, 03:21 PM
Buy or make a plastic reducer fitting that will slip over the outside of the threaded portion and use plenty of glue.

SGW
08-06-2011, 04:05 PM
I'm a bit confused; is the 90 degree ell at the bottom metal, or plastic with a metal thread insert? If you want to change it, why don't you just unscrew it and change it? Presumably if you can cut the pipe above it, and weld to it, you also have access to the ell. or could enlarge access to the 90 degree ell with a hammer and cold chisel and possibly a masonary bit to speed up the process.

But otherwise I like Evan's idea. Bore out a PVC fitting to a slip fit over the outside of the 90 degree ell and put the glue to it, possibly including some glue on the crack inside of the ell to be sure it seals.

The next person to work on it will have unkind thoughts about "whoever the h*** did this repair," but I wouldn't let that stop me. :D

darryl
08-06-2011, 04:44 PM
Is there a short straight junction piece that would fit the diameter of the bottom leg of the T ? Maybe there is, or not. If you can find some larger diameter plastic tubing that can be bored slightly to use as a junction, then you have a fix. When pieces fit together with a slight interference fit, solvent welding works great.

Pvc can be heated to softening point in the oven. Sometimes it will shrink in diameter. If you find some tubing that's just a tad large inside, you might be able to shrink it and re-bore it to fit as a junction.

taydin
08-06-2011, 04:48 PM
I'm a bit confused; is the 90 degree ell at the bottom metal, or plastic with a metal thread insert?

It is plastic with a metal thread insert. The rest is all welded plastic.


But otherwise I like Evan's idea. Bore out a PVC fitting to a slip fit over the outside of the 90 degree ell and put the glue to it, possibly including some glue on the crack inside of the ell to be sure it seals.

I think you and Evan are talking about a piece like this:

http://www.pilsa.com.tr/urunler/pp_rboruyeni/ppia.jpg

So take this, make the outer surface nice and round on the lathe. Also remove the plastic fitting end. Make a plastic pipe that fits to the outside of the ell on the wall and this part that came out of the lathe. Glue them together.

The faucet would be too far away from the wall with this arrangement, though. Currently, the thread is sticking out 15mm. With this attachment, it will be sticking out close to 50mm.


The next person to work on it will have unkind thoughts about "whoever the h*** did this repair," but I wouldn't let that stop me. :D

I had similar words to say to the guy that put together this unmaintainable mess :)

taydin
08-06-2011, 05:14 PM
Is there a short straight junction piece that would fit the diameter of the bottom leg of the T ? Maybe there is, or not. If you can find some larger diameter plastic tubing that can be bored slightly to use as a junction, then you have a fix. When pieces fit together with a slight interference fit, solvent welding works great.

The material of this plastic is called Polypropylene Random Copolymer. It can be easily heat welded, but I am not sure whether it will dissolve in solvent. I will try that tomorrow. But if it doesn't dissolve, what would be the best type of glue to use on PP?

If these were PVC-U, then there is special glue available that melts the plastic and perfectly seals the junctions. It is called "Tangit" and is widely available here.

plunger
08-06-2011, 05:53 PM
Expose the pipe and cut the pipe to the left and right of the tee. Buy two plastic couplers and bore the coupler right through to make a slip coupler. Buy a new tee and female elbow and use the tangit.One hour drying time per bar of pressure.If it is not pvc but is 15mm od buy speedfit fittings or use conex fittings and change the piece to copper or pex.

taydin
08-06-2011, 08:20 PM
plunger, the terminology is quite different here for fittings, so I'm still trying to understand the setup you are talking about. So I'll take a brass T and attach this type of couplings to the left and right end:

http://www.pilsa.com.tr/urunler/pp_rboruyeni/m_ppdr.jpg

Then weld the plastic side of the couplings to each plastic pipe end. I guess the cut distance between the pipes needs to be quite precise in order to guarantee that the couplings seal when they are tightened, but it will work. If I screw up the distance, I can always go to my mill and machine the T so that it will fit nicely :D

Am I understanding your solution correctly?

Evan
08-06-2011, 08:43 PM
Polypropylene doesn't glue at all well with anything. Make a tight fitting metal collar for the current fixture and install with silicone sealer. That should prevent the crack from opening. Use sealer to install the faucet.

davidwdyer
08-06-2011, 08:59 PM
Can you cobble something together? Like putting a lot of sealer on whatever screws into the elbow, then putting a hose clamp around the fitting and tightening it to close up the crack?

I suppose it depends on if you are renting or own as to how much trouble you want to go to. Also, in Turkey, the availability of parts might be limited.

plunger
08-06-2011, 09:02 PM
The picture you are showing looks like a male union. On the left of the picture ,the white piece is that meant to be glued to a plastic pipe. if so you could cut out the entire tee and use a tee with female threads all round. The unions will make it easy to connect up. i am unfamilier with that fitting but in my country we work mainly with copper or plastic pipe that is mainly 15mm od. We have compression fittings that will tighten on the pipe It has a ferrule that looks like a wedding ring. If it is 15mm od you could use two compression fittings,one on each side of the tee that you cut out. A brass compression fitting normally has a stop ring in the center of the fitting to stop the pipe from sliding passed the middle of the fitting. If you bore that out it becomes a slip fitting so that you can slide the fitting along the pipe. This allows you to measure exactly the length you need to cut from the tee to the pipe you have cut to remove the tee.Look up( conex fittings europe )

taydin
08-14-2011, 09:18 AM
Here is the finished repair. The pipe on the left is 1/2" and the one on the right is 3/4". I cut away the plastic tee and welded appropriate size male unions to the pipe ends. When measuring the amount to cut, I made sure to err on too little instead of too much.

Then I took a brass tee and attached the male unions to both ends. As per murphy's law, the tee with the unions didn't fit between the pipes. So I went to my home shop and used my lathe to shave off 4mm from each end of the tee. I also shaved off 3mm from the threaded end of the male unions. The result was a perfect fit :)

I confirmed for one week that there was no leak and then started filling the crack with grout and pieces of brick. Once this dries, I'll do the tile work.

http://www.taydin.org/web/tesisat_ariza/scaled_img_11.jpg

Carld
08-14-2011, 10:15 AM
Looks like it should work. I hate pipes embedded in concrete expansion and contraction destroys them. They should have been covered with the foam sleeves used for freeze protection but hardly anyone does that.

lynnl
08-14-2011, 12:36 PM
"no leak" huh?

What's that I'm seeing on the bottom of each connection that looks so very similar to a water drip just waiting to fall? :D

Duffy
08-14-2011, 06:00 PM
Taydin, if those unions are steel, then you are about to bury a "time bomb" in your wall. They form a galvanic couple with the Tee, and will preferentially corrode. The rate will depend on, among other things, the amount of dissolved salts in the water. With luck, you wont care, but it IS gonna happen, sooner or later.

davidwdyer
08-14-2011, 07:22 PM
Duffy may be right about corrosion, but if Turkey is anything like Brazil, you are probably happy to find fittings which "fit."

Congratulations on being able to fix the problem.