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johnL
pex supply blew apart

Okay, folks, what happened here?
LUCKILY, luckily, we were in the middle of dinner when this hot water supply under the kitchen sink blew apart. If we had been gone...:eek::(
I put this in only about a month ago. It hasn't leaked one drop since then. Our water pressure is only 40psi. Before moving to this house, I had never even seen this type of supply line. So what did I do wrong? As you can see, the pex line just blew right out of the compression nut. The ferrule (or whatever it's called) is the plastic kind that came with the pex line. It looks like the line is plenty long enough. I figured if it wasn't leaking it was tight enough.
Help please.

Nestor
Re: pex supply blew apart

The first thing to check is to see if the tubing BROKE or not. Take the compression nut off the top of the valve and see if you can fish the plastic ferrule and any bottom to that tube out of the valve.
If there is no bottom to that tube to be found anywhere, then the tube was simply cut too short.

If you pull more than a half inch of tube out of that valve, check to see if the top of it is lighter in colour than the bottom (indicating stretching) and check to see if there's any marks on the bottom of the tube.

If you have another one of those valves, see if it's possible to stick the plastic tube into it so far that the tube interferes with the movement of the valve spindle. I'm thinking that opening and closing the valve could have caused the tube to bend, causing cracks to form around the tube.

Did you notice anything odd when opening and closing that valve?

PS: That's not PEX tubing. That kind of plastic tubing has been used as supply tubing for faucets and toilets since long before PEX tubing came out. It might say PEX on the tubing, but if that's the case, it was simply made by a company called PEX.

johnjh2o
Re: pex supply blew apart

It looks like it wasn't in the valve far enough or he had the ferrule on upside down. As far as I'm concerned that is the best supply on the market. At least he used a plastic ferrule. I have seen failures from using brass ferrules on Pex supply tubes. They tend to cut the supply tube.

John

canuk
Re: pex supply blew apart

It was a good thing you were home.

Problem --It's a compression fitting ( which I'm not much of a fan ) and likely the cheap compression ring got distorted when installed . Just took some time to finally let loose. Personally I would use a barb fitting with a crimp ring

johnjh2o
Re: pex supply blew apart
canuk wrote:

It was a good thing you were home.

Problem --It's a compression fitting ( which I'm not much of a fan ) and likely the cheap compression ring got distorted when installed . Just took some time to finally let loose. Personally I would use a barb fitting with a crimp ring

cauk I think that's a PEX supply tube not a piece of Pex pipe. They a meant to be used with compression nut and plastic ferrule.

John

canuk
Re: pex supply blew apart
johnjh2o wrote:

cauk I think that's a PEX supply tube not a piece of Pex pipe. They a meant to be used with compression nut and plastic ferrule.

John

Had another look at the photo -- you're probably correct on the pipe.
Though the compression ring ( ferrel ) let go.

johnL
Re: pex supply blew apart

Okay, the ferrule looks perfect, and I had the narrow end down.
There was no more tube in the fitting, so it didn't break, however it can only go in 3/8 inch; that's as much room as there is. There's a ledge that prevents it going any further. And the tubing doesn't interfere with the spindle turning.
I should note that there was the same type of tubing on there when we bought this house; so it couldn't have been in any further than this one was. (I had to get new tubing when I replaced the faucet because the old one no longer reached.)
Something I've noticed: I pulled the same type of tubing off of a bathroom faucet just a couple days ago. In that case, the ferrule was crimped so tightly to the tube that I couldn't even get it off. I finally did get it off, with pliers, and noticed that the tubing had a serious crease around it from the ferrule. But my tubing that just popped off doesn't even have a mark on it from the ferrule. That's why I wondered if I didn't get it tight enough.

Thanks, guys. (And my tubing doesn't say pex, but the label does.)

johnjh2o
Re: pex supply blew apart

It is Pex it's just has a preformed head on it. I would say you didn't tighten it enough when you installed it. I would check the one on the cold side so you don't have a replay.

John

johnL
Re: pex supply blew apart

How tight is tight enough? The braided steel hoses that have compression fittings with the built-in rubber washer say hand-tight plus 1/4 turn. If you tighten them too much, they leak.

johnjh2o
Re: pex supply blew apart
johnL wrote:

How tight is tight enough? The braided steel hoses that have compression fittings with the built-in rubber washer say hand-tight plus 1/4 turn. If you tighten them too much, they leak.

They have a rubber washer. That fails more often then a ferrel.

John

johnL
Re: pex supply blew apart

So do I want to get this as tight as I can?

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