PEX cinch or crimp best?

I plan to redo some plumbing in PEX. I have pretty much decided against using Sharkbites due to long term cost and possible freezing issues. Now I need to decide between cinch or crimp clamps. I thought I had heard that crimp was better but a plumber I talked to says that he now only uses cinch and likes them better.

Which is better, cinch or crimp and why? Freeze protection is my primary concern but I would be interested in other issues like ease of use.

BTW: My contractor says they ran a test freezing PEX and it expanded but never did burst or leak.

There's a third choice - the Uphonor expansion system. This one relies on the natural property of the tubing to return to the original size. You insert a tool, expand the end and a reinforment ring (at the same time), then slide a fitting into the now larger pipe, and hold it for a moment while the tubing collapses around it. Done. It also has less restrictions, as the fitting of the other systems must fit inside the 'normal' ID of the tubing, further reducing its diameter.

It's the fittings that can burst, not the tubing. This is true for all systems. While unlikely, a freeze issue could in theory, loosen a crimp or cinch, but would tighten the expansion system, if it didn't burst the fitting.

dinotoad said:

BTW: My contractor says they ran a test freezing PEX and it expanded but never did burst or leak.

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Sorry but he lies. I have gone and fixed MANY in-slab heat systems that have frozen and sprung leaks.

If the PEX in in the concrete, HOW does it expand enough to split? Cinch fasteners only need one tool, and you do not have to change dies when you change sizes.

I would use the SSC cinch clamps in your application...

Doherty Plumbing said:

Sorry but he lies. I have gone and fixed MANY in-slab heat systems that have frozen and sprung leaks.

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PEX for the most part is very resistant to freeze damage...
In fact as long as there is more than 7" between connectors damage is unlikely...

Of course the AL-PEX-AL commonly used in heating systems is one of the few types of PEX that cannot freeze without damage...