It seems the ease and reliability and no water pressure loss of the expansion connections makes them far superior to the alternative.

So besides slightly cheaper materials cost and less expensive tool what is the advantage of using the crimp/clamp connection?

  • 1
    Regarding the pressure loss: (Having taken a few fluid dynamics classes), I can assure you that the pressure loss across a few short slightly smaller cross sections (fittings) is fairly insignificant compared to the losses in the tubing itself. So, unless you have very short runs and plan to undersize the supply line, pressure loss is not an issue.
    – Paul
    Commented Jun 11, 2015 at 19:24

2 Answers 2


You'll find the crimp fittings are a lot more available. I have found no local retail plumbing stores in my entire metropolis which sell the expansion style of anything. Also, there is no warranty on the expansion type unless you're certified so I'm told. Not that warranty claims on any plumbing install are that common or plausible anyway.

A lot of plumbers prefer expansion because it's more reliable to install. They claim, they have fewer leaks and they don't even check their fittings. Some plumbers claim it's more durable against things like frozen pipes etc. And, you get less friction due to the interior size of the fittings being larger - that is obvious due to the nature of how they are designed. However, I personally have never had issues with restricted flow anyway.

I've put in thousands of miles of crimp style pex and never once had one of my fittings fail. Never the first time, and never later to my knowledge save a couple of cases where someone's house heating failed and the pipes froze (still not as many issues as I've seen with copper pipes failing due to freezing.) Some of those installs are approaching 10 years old, I've heard of no issues. I use the cinch style clamps, not the copper rings. Mostly because if I have to remove something, it's easier. They are easier to work with in cramped areas as well and from what i've heard, they hold up better than copper.


As I understand it, the expander only works on PEX-A tubing which is more expensive and not as durable/chemical resistant. I have found that in many instances I had to make a connection in a tight space and needed the compact compression ring tool. The expander has the advantage of working before the connection is made, so I suppose if you plan ahead you can avoid using the tool in a tight space, but the tool looks a bit more difficult to use in, say, a crawlspace where you'll be lugging around an extension cord everywhere you go.

Just my 2 cents. I've never used an expander before.

Edit: It also appears that contractors complain about the expander not working in cold conditions.

  • I have skimmed that page a few times and missed the part about "durable/chemical resistance". I really would think the pressure tests would be better on PEC-A! Commented Jun 11, 2015 at 19:06
  • Correction: Expansion fittings only work with PEX that has sufficient elasticity. All PEX-A has sufficient elasticity, but certain brands of PEX-B also have sufficient elasticity and are explicitly marketed as being compatible with expansion fittings. At the time of writing, this includes Zurn and Sioux Chief, potentially among others that I'm not yet aware of. I was very happy to discover this, as it means I can have the security of expansion fittings without the chemical downsides of PEX-A.
    – M-Pixel
    Commented Jul 6, 2022 at 18:00

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