pex versus pex-al-pex, dimensions, fittings, viega can do both?

lolo21

Can someone explain me or point out why viega claims its rings and tool can do both pex and pex-al-pex?

I have check both astm specifications and 3/8" and 1/2" tubing ID and OD is close for both materials but when you go up to 1" the ID of pex is much smaller.



If you use the viega tool and rings can you still use the same fittings for both materials even when the sizes are so different?



I have a ton of pex fittings, tools etc... and would like to start using pex-al-pex on certain places. I bouth 1" pex-al-pex and a regular 1" pex fitting is much, much smaller so I dont understand how viega can do both.



There's also a few guys in the internet who sell crimpings tools and cooper rings sized to the ASTM standard for pex-al-pex. Has anybody tried using these with regular 1/2" fittings since the ID-OD are so similar?

I am curious and I don't care about "not recomended by manufacturer" or warranty issues.

Iwould like to know if I would need to buy all fittings twice for all sizes before buying more crimping tools. Thats one thing I like about the ss clamps: one tool=all sizes. Also it seems like no one sells valves for pex-al-pex other than 1/2".

thank you

Paul Pollets

Viega fittings

Viega fittings are interchangeable with both their  PureFlow and Fostapex lines. There is a special reamer tool used to trim a layer of the Fostapex (Pex-Al-Pex) to attach the fitting. I''ve been using theses fittings for many years and never had a leak or a problem. The fittings will not work with certain sizes of Pex-ll-Pex( ...like 3/4"MultiCor)  It's also worth the investment to use  the 18v portable presstool with seperate jaws for both the press fittings and the copper press fittings. You'll be amazed at the ease and speed of connections.



I've used the SS crimp rings, they work well for certain applications and hybrid repairs.