PEX (polyethylene in a crosslinked matrix) is a relatively new plumbing material that is becoming more popular and is now required by building codes for use in both old and new construction. PEX is a flexible tubular plumbing system with compression, metal or plastic insert fittings, or other mechanical methods that do not require glue or heat to connect. CPVC is a hard plastic piping system with jointed joints that are glued together.
CPVC and PVC are two different types of plastic that have varied applications. Because they aren’t often used in the same applications, CPVC and PVC aren’t commonly found together. CPVC is chlorinated in an extra step, which allows it to endure high heat levels much better than normal PVC. While at temperatures 140F, PVC begins to deteriorate, CPVC maintains its strength up to 200F, making it ideal for water supply lines. Because it is less expensive and does not rust, PVC is most frequently utilized in drain lines. But if necessary, could you glue PVC to CPVC?
The most common (and inexpensive) material used in the manufacture of Pex is CPVC, which cannot be bonded. There are no compression fittings for cpvc, at least none that can be utilized in a house. Each type of pipe will require an adapter to pipe thread connection. The PEX adaptor will be crimp or whatever brand of PEX uses, and the CPVC adaptor must glue on.
CPVC and PEX Explained
CPVC — Chlorinated Poly (Vinyl Chloride)
CPVC (chlorinated poly (vinyl chloride)) is a durable and resilient thermoplastic material that’s commonly used for hot and cold potable water applications in residential construction. Because it’s made of polyvinyl chloride, CPVC is resistant to damage from highly chlorinated domestic water and has a greater temperature tolerance than PVC. Before your home’s water reaches you, public water companies employ chlorine-based disinfection to destroy pathogenic bacteria. Disinfection methods and levels in water systems can differ somewhat without notice, depending on your location and season. Corrosion resistance is CPVC’s primary advantage over PVC.
PEX — Cross-linked Polyethylene
Medium- or high-density polyethylene is used to make PEX pipes, which are flexible and sturdy. For decades, PEX piping has been utilized in hot-and cold-water distribution systems as well as hydronic radiant heating in Europe. The United States was introduced to PEX pipe in the early 2000s. In the 1980s, PEX is the most widely used flexible piping for plumbing and radiant floor heating applications. PEX tubing is easy to work with because it can be easily snaked through the walls, making it a common selection for remodels. Water distribution pipes made of PEX tubing are compatible with all major plumbing codes, making it an excellent choice for your house. Learn what happens after the PEX manufacturing process is complete.
PEX and CPVC Compatibility
The most frequent PEX plumbing line connections employ a specialized tool to seal the tubing to the fitting. A compression ring and nut are used for other types of connections. The CPVC pipe fittings are secured to the CPVC with a solvent-based glue that fuses the pipes to the fittings. The PEX tubing will soften when heated, and the connection will not remain stable. PEX is a flexible plastic that is not compatible with CPVC fittings, since the rigid plastic cannot be crimped into position for a crimp system and will not spread to work with a compression ring and nut for a compression fitting.
Push fittings, on the other hand, work with all forms of plumbing pipes, including PEX and CPVC. The fittings utilize an O-ring to keep pipes against an internal gasket, similar to a quick-release fitting on a water or air hose. Push the PEX tubing into one side of the fitting and the CPVC tubing into the other side of the fitting, and you’ve got yourself a connection without any glue or special tools required for CPVC or PEX plumbing systems.
Is PEX and CPVC the same size?
It is also worth noting that PVC and CPVC pipe are identical in most respects, with the exception of material composition. The pipe is inserted into a CPVC fitting, which has fittings that are similar to copper in design. PEX pipes have an internal diameter reduction at each fitting, even when “full flow” expansion fittings are used.
Why is PEX plumbing bad?
The PEX plumbing system has been in use for a longer period of time, thus its failures have been witnessed and recognized. The major failure of the PEX system is caused by piping and fittings. When water containing chlorine comes into contact with the pipes, they fail.
How to Join PEX and CPVC
The use of push fittings is becoming more common in plumbing. There are several manufacturers of this sort of fitting, and they’re now available at regular home improvement stores. The fittings are pricey, but they’re far less expensive than continual blunders or having to move entire plumbing lines to another system for compatibility. Because the fittings may be reused, making a mistake or altering the system won’t necessitate buying new ones.
Remove any debris from the end of both PEX and CPVC pipes. Examine each pipe for burrs, nicks, cracks, or damage; then remove them with a razor blade on the PEX or sandpaper on the CPVC side. A smooth, finished end on the end of whatever sort of pipe is put into the fitting is essential for proper seal. Place the push fitting on the CPVC pipe and firmly press it against the pipe until the latter cannot be inserted any further. Since CPVC is a more stationary pipe, it is fitted first. Move the end of the PEX tubing over to the other side of the push fitting and press it firmly and fluidly into the fitting. Turn on the water and check for leaks.
In order to successfully connect two PEX pipes together, you must use fittings with the name “Sharkbite” or “SeaTech.” You may not weld, seal, or attach pieces of PEX line directly to one another either. Look for fittings labeled “SHARKBITE” or “SeaTech” if you want to do any of the above.
Steps to connect PEX to PEX?
- Remove the excess PEX tubing from the flashing.
- Slide the PEX crimp ring over the tube about 2″ past the end.
- Fully push the PEX fitting into the PEX tubing until the shoulder of the fitting touches the tubing.
- The PEX crimp ring must be positioned 1/4″ – 1/8″ from the end of the tubing.
- Using the PEX crimp tool, open the jaws.
How do you fix a leak in a PEX pipe?
How it’s done:
- Remove the leaking/damaged section of PEX tube using the PEX tubing cutter.
- Prepare a new piece of PEX tubing that is slightly longer than the length required to make the repair.
- Connect the tubing to fittings by using a Crimp Connection Method and check the connections with a Go-No-Go gauge.
The most common PEX plumbing line fittings include fittings that require the use of a specific tool to crimp the tubing onto the fitting. To join the pipes and fittings, CPVC pipe connections are fastened with a solvent-based glue. The solvent-based glue will soften the PEX tube, and the connection will not stay together.