In addition, there is a difference in water flow between the different PEX systems.
The crimp ring and stainless steel cinch clamp methods both rely on fittings being inserted into the PEX tubing. The rings or clamps are then crimped or cinched on the PEX tubing to make a water tight seal on the fitting. But note that the inside diameter of the fitting is smaller than the inside diameter of the PEX tubing. This causes turbulence and flow restrictions.
In contrast, the Wirsbo/Uponor PEX system relies on expanding the PEX tubing (and a PEX ring) and then the fitting is inserted. Then the PEX tubing and ring contract over the fitting making a water tight seal. This means that the ID of the fitting ends up approximately smooth with the ID of the PEX tubing which creates less turbulence and no flow restrictions due to smaller ID sizes of the fittings.
Ideally, PEX should be installed with a minimum of elbow fittings and use gradual bends instead. Aside from reducing the amount of installation work, this also improves water flow. This is true regardless of which PEX system is used. Optimally, there should just be one connection at the source and one at the destination with no elbows in-between. Less fittings in PEX systems compared to copper allow water in PEX systems to flow better.
Last edited by Homerepairguy; 03-24-2012 at 08:32 PM.