PEX Plumbing Part 7, Specialty Fittings
SharkBite Fittings: These are manufactured by Cash-Acme and use a “push – fit” connection system and can be used for potable ( drinking ) water systems and Hydronic heating systems. Connections are simple and made by pushing the pipe into the connector with a twisting action until it clicks. Complete and well detailed instructions can be found on the Cash-Acme web site. A specialized tool is needed for disassembling the connection, but this is also a quick and easy operation. The connection has a stainless steel grab ring with teeth that open out and grab onto the inserted tube. SharkBite fittings are approved for behind wall and underground applications. These fittings may be turned or rotated after connections are made for installation in tight spaces. SharkBite fittings are considerably more expensive than regular PEX fittings but depending on your application you may find the ease of installation worth the increased cost.
BrassCraft has a SureConnect with Vitron o-rings with a similar “push and lock” system. These connections can not be rotated after assembly.
ProPex Fittings. These are manufactured by Uponer, formerly Wisbro. They require the use of specialty ProPex expansion tools and ProPex rings and are an expansion style fitting. The system expands the tubing and then uses the Pex’s “shape memory” retention and a compression ring to assure the connection. From my research the system is very solid but may be difficult for the average “do it yourselfer” to work with. The ProPex fittings are designed to work with AQUAPEX (PEX-A) and hePEX (oxygen diffusion barrier) tubing. Would they work with any brand of regular Pex tube… possibly. I can not guarantee this but the system relies on the expansion and contraction of the material and most Pex tube works this way. I would doubt that it would work with Pex-al-Pex, the aluminum middle type Pex. One interesting note I have found is that you should not do any soldering work within 18″ of an AQUAPEX connection, so it seems the excessive heat could effect the compression connection.
PEX Press connection system by Viega, also called PureFlow. These Press fittings require the use of the Viega PEX press tool and Press sleeves. The sleeves are stainless steel and provide a view hole to assure full tube insertion. This connection system works with standard Pex, oxygen – barrier Pex and Pex-al-Pex.
Failsafe Plus fittings. These fittings are by Marshall Brass. Very similar to a standard Pex fitting but these have recessed o-rings, “below the barbs” for extra sealing assurance. They can be used with any standard copper or stainless crimp – clamps and installation tools.
Again, specialty fittings and any tools that are required for them will be more expensive than the standard Pex fittings but depending on your needs you may find them to be well worth the extra costs. If you have used some of the fittings described feel free to contact me with any information you wish to share.
As an additional note: You may also see Pex fittings that are made for Pex to Polybutlyene connections. What is Polybutlyene? It is a co-polymer tubing widely used from the mid 1970’s to mid 1990’s. Deterioration and failure rates of Polybutlyene systems are extreme. Polybutlyene can be identified by it’s grey color for interior applications or blue, grey or black exterior use. It is rigid or non-flexible. Do not confuse it with black poly with polythelene tubing or with PVC or CPVC. (PVC or CPVC would be found mainly in drain connections.) If you are unsure ask an expert. All I can say regarding this is that if I had it in my home I would replace it. With that in mind, I do not use the Pex to Polybutlyene connectors.
