PEX Crimp Rings - Possible Installation Problems

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HaydenTO

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Hello.
Love these forums. This is my first post.
OP updated with my findings in red. Thanks all for your input.

I'm a Construction Manager and I have a plumber on a job using PEX with crimp rings and I think he may be a bit of a cowboy. I don't need to discover leaks in walls down the road so I checked some of his crimps. I understand how the PEX Copper Crimp tool works and how to check with the double sided Go/NoGo gauge tool (different spots on gauge to check Go and NoGo). My questions are these:

1 What if the GO side if the gauge tool fits but it is a bit hard to press on? Is this still a good fit or should it slip on easy? (videos seem to suggest it should slide on without resistance)
Answer: Gauge should slide easily over crimp and not need to be forced on.

2 What if the GO gauge fits but then does not fit same crimp when tried at 90 degrees from first check (meaning crimp may be slightly oblong)? Is it still a "Valid crimp" if the GO gauge fits at minimum somewhere around the crimp?
Answer: I was told by one Sharkbite rep that the crimp may leave tiny nubs at the point where tool teeth touch. In that case the gauge may not slip over this specific part of the crimp. The other said it should fit any way it is put on. I tested several crimps from two different tools on 1/2" PEX (with and without fittings), and found all my crimps were near perfect circles and the gauge fit easily and was able to swivel around the pipe/crimp easily. So my thinking is the answer to this question is it should fit one way then 90 degrees to that check. If it does not fit well all around the crimp you may have an oblong/oval crimp which I would suspect could be caused by a tool needing calibration or replacement.

3 Related to question 2 above... Can you re-compress a crimp a second time to correct one that may be out of round? In other words can you use the compression tool more than one time on a single crimp ring?
Answer: Tech consensus from Sharkbite reps is that crimping more than once may be acceptable so long as the gauge tool fits well in the GO spot but still does not in the NO GO spot (meaing you did not overcrimp). I also spoke with someone in the field who said years ago some plumbers would always double crimp at 90 degree offset to ensure a full seal.

4 What if you have to press hard to fit the Go gauge onto crimp ring and then when trying to swivel it around to check roundness the gauge is so tight that it does not slide around the ring but the crimp ring actually rotates around the PEX tubing as the gauge is turned. Is this a sign of a bad connection? Or ok?
Answer: Tubing/Fitting/Crimp rings should not spin easily once crimped. A good seal should hold everything quite tight together and things should not spin.

I'd love it if someone said that I am being overly paranoid and not to worry. But I have to be. Risk Management is my job! I'd rather fix a small problem now than a huge problem later.
:)

Thanks
 
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Cjlambert

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Canadian code requires an air-pressure test of the system at 101.5 psi for 1 hour with no drop in pressure.

Put an air test on it. If everything holds, you’re all good.
 

HaydenTO

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The go, no system is very unclear.

Fundamentally it is pretty simple and clear (crimp should fit in GO gauge and not fit in NOGO gauge - or part way in and not fully depending on which version of the gauge tool you have). BUT the added info relating to my questions above is what is missing to get the full picture on how to diagnose a good crimp from a potentially bad one.
 

HaydenTO

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Canadian code requires an air-pressure test of the system at 101.5 psi for 1 hour with no drop in pressure.

Put an air test on it. If everything holds, you’re all good.

Although I agree this would be the proper way to test the system. This is a reno project so not likely to happen. Still does not answer the questions unfortunately. :(
 

Jadnashua

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Just a theory here as I've not used crimped pex...doesn't the tool make sort of two dog ears as it compresses around the tubing? If so, those ears would be tight, while the rest of the thing would be compressed to fit the go/no-go tool. Take a look at a ring you might compress with just the tool so you can look at it from the side to see what actual shape it is in. It's probably not a nice circle without imperfections.
 

HaydenTO

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Thanks James Henry I totally agree.

I have updated my OP with my findings. I hope this helps others. :D
 
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