Heating Help

Compression vs press fittings for Pex-Al-Pex

I'm installing radiant heating with Everhot Pex-Al-Pex tubing and they
say that I can use either compression or press fittings. Does anyone
know which is better and why?



Also, does anyone know how bad a scratch on a pex-al-pex tube has to be
before its unusable? The manufacturer says stuff like, "don't step on"
and "don't scratch" but installing it seems impossible to not get it
scuffed up a bit. I was wondering if anyone knew what kind of scratch
was too much?

Pros and cons

Neither fitting style is better.  I use both and they both work well.  Crimp is more permanent, but sometimes harder to use the tool in tight spaces.  Compression is nice for a service stand point it can be used as a union.  I like to use semi-permanent lock-tight on compression threads when i cover them up, to eliminate the loosening of threads from expansion and contraction. 

As for the scratches?  I have used PAP for 10yrs now and I have not thought to much about scratches, more so I worry about kinks, cuts and holes.  I like PAP because of the lower expansion rate, closer to copper than PEX, which ensures a quite system operation.  Also i like the fact that the pipe holds its form and does not wack you in the face.  Also, looks nice cuz you can make it straighter than pex.

Jeffrey