PEX Fittings & Pipe Compatibility
PEX crimp fittings - these fittings are universally compatible with all types of PEX pipe (with the exception of PEX-AL-PEX) and are used together with crimp or clamp (cinch) method for making a connection. This method is time-tested, reliable and affordable, making it the most popular choice for PEX tubing installation in the USA.
PEX expansion fittings - compatible only with PEX-A tubing (any brand) or expandable PEX-B tubing (special type of PEX-B pipe which, unlike standard PEX-B pipe, can be expanded) and are installed using an expander tool and expander sleeves. This method is also time-tested, proven to be very reliable and takes a rightful 2nd place in popularity. What sets it apart from others is that the ID (inside diameter) of the fittings is substantially larger than with all other types, allowing for more flow and less pressure drop. The downsides of this method are a higher cost of fittings & components and difficulties with installing in a cold climate/environment.
PEX press fittings - Viega PEX press system offers a unique approach by integrating a steel press sleeve (comparable to a standard PEX crimp ring or cinch clamp) into the fitting, which effectively reduces mistakes & installation time. Press sleeve has a larger contact area than typical PEX crimp rings or clamps and thus ensures an exceptionally solid & secure connection. Another big advantage of this system is that it is also compatible with all PEX pipe types. It has proven to be a reliable and user-friendly solution, but does come at a significantly higher cost (comparing to crimp and expansion fittings) and requires Viega proprietary PEX press tools.
Push fittings - a unique fitting system which is compatible not only with all types of PEX, but also with copper (K, L, M) and CPVC pipes. These fittings require no special tools, are very easy to install and can be easily disconnected if needed, making them the quickest and most convenient of all. They also allow for an easy transition between different pipe types. The main disadvantage of this method is the cost, which is the highest of all others.
PEX-AL-PEX compression fittings - are intended for use with PEX-AL-PEX pipe only. They will not work with PEX tubing due to dimensional differences.
