Is pex flexible enough on case I do not get the perfect height between the 2 sharkbite fittings? Or do they need to be more or less perfect?
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The sharkbite fittings go over some 1 inch pex pieces easy but not others. They are smooth on the outside. The only thing I can see a slight curvature in the pex from the coil. Any experiences with this?
I recently posted some pictures of a repair on my Facebook page. The client claimed she had someone else in to install a shutoff valve. They used sharkbite fittings and left the homeowner with a bunch of leaks (according to the customer). They asked for it to all be replaced so I returned it to the copper tubing and soldered fittings that the rest of the house had. Solid fix, no leaks, I was happy about my first major plumbing repair. Unfortunately, people absolutely lost their shit in the comments defending sharkbite fittings and shitting on my work for not just redoing the sharkbites properly and adding a fitting that was missing. I've always heard sharkbites were kind of hacky and better suited to temporary repairs or diy fixes. What do you all think about sharkbites?
Sharkbite makes "slip couplings":
Home Depot source
These are designed to slip deep over one end of a pipe, to allow a fix pipe like your PEX segment to get in place, then slip back for the final connection. The "About this product" section on the Hope Depot link claims that this device can handle a 2" missing segment of pipe. If you cut clean that damaged copper pipe end and properly size the length of replacement PEX, you can slide a slip coupling on the copper pipe and slip it back over the PEX end, and the repair is complete.
(The product is shown for example purposes only, I'm not affiliated with this product or Home Depot.)
Replace more (throughly unbendable) copper with (slightly bendable) PEX. If you can replace the copper to a point where it turns 90 anyway, one 90 and one straight will get the job done easily while (as @keshlam has already noted) the stock solution to a short splice in a stiff line is four 90's. In a longer straight line situation you can loop or wiggle the PEX (respecting minimum bend radius) or you could use 2 90's and a U-Bend (respecting minimum bend radius) of PEX between them. That might be better done to the next joist bay or the one after that to keep the bends large.
3 foot section of copper pipe that had developed a pinhole leak. ... Our water here (Vancouver BC) is really soft.
While it could be the fitting, my initial reaction to this confluence of factors is "Well, then copper pipe is a terrible idea, and replacing a single section of copper pipe due to a pinhole is doing nothing about all the other sections of coper pipe being eaten by the water."
Where copper pipe is eaten by the water chemistry, you either need to alter the water chemistry or use pipe that does not corrode. And if you are replacing copper pipe that has been eaten, you need to look large-scale, because every bit of copper pipe in your house has been exposed to the same water for roughly the same amount of time.
So my first guess would be that the leak is most likely coming from the pipe beyond the replaced section.
My view on Sharkbite Fittings:
They are great for exposed plumbing. Especially for water heaters. They make a great quick disconnect system for appliances. I also am a big fan of their shutoff valves.
What I would not use them for us concealed work behind walls and ceilings. They are rated for it it they claim the rubber seal will last more than 20 years and are resistant to deterioration from corrosive water. But I simply don't trust them. I want my pipes to last 50 years.
The key to a good sharkbite connection is proper preparation of the pipe. Of you're using PEX, it's a no brainer. If you're using copper, you need to properly debur the fitting. Inserting a jagged sharp edge of copper into the fitting can tear the rubber o ring inside the sharkbite fitting. Also, don't use Emery cloth the clean the end of the pipe like you do when soldering. This can also cause a leak.