Plumbers and do-it-yourselfers have benefited from cross-linked polyethylene pipe with its simple design. It is flexible, allowing it to bend in just about any direction. It’s also available in red and blue, making it easy to distinguish between hot- and cold-water lines. And fortunately, connecting PVC to PEX is easy to do.
Whether you’re looking to repair or expand your plumbing, adding PEX to your existing system is accomplished using a threaded fitting. In general, a fitting comes with one half to attach to existing pipe, and another half that fits on the PEX pipe. Threading both halves together creates a watertight connection.
Pipe connections can be made using the following types of fittings:
- Expansion Fittings: You’ll need a PEX expander tool, which stretches the diameter of the pipe so you can place the fitting. Since PEX will return to its original size, it creates a watertight seal around the fitting once you remove the tool.
- Compression Fittings: Before inserting the fitting, you must slide a brass nut and plastic compression ring over the PEX pipe. A metal sleeve is then inserted into the pipe. Next, insert the fitting, tighten the nut, and create a seal by squeezing the compression ring.
- Crimp Fittings: Metal rings are slipped over the end of the pipe. You can then insert the proper fitting, but a PEX crimping tool is needed to tighten the ring over the pipe and fitting.
- Clamp Fittings: Installation is similar to the crimping process. However, a ratchet clamping tool is needed instead of a crimping tool. It tightens the steel rings on the PEX pipe after the ring is placed. The fitting itself goes into the end of the pipe while the ring is positioned over the fitting and compressed via a side tab using the clamping tool.
- Push-Fit Fittings: Clamping or crimping are not necessary for these fittings. They are the simplest to connect and don’t even require tools to attach PVC to PEX To make the connection, just insert the PEX pipe into one end of the fitting; it will lock into place internally.
Making a Connection with Threaded Fittings
If using a threaded fitting, the side connecting the PVC pipe must be a male plastic fitting. It connects to the metal female fitting for the PEX pipe. Connecting a metal male fitting to a plastic female fitting can strip the threads or crack the plastic material.
To make the attachment, brush a PVC primer on the fitting and pipe. This will clean the PVC and soften it slightly. Next, apply glue to the end of the pipe and within the fitting. You can then slip the fitting over the end of the PVC.
On the end of the PEX pipe, place a matching threaded female fitting. Aside from the push-fit connection method, this can be used with all methods mentioned above. However, the fitting must match the connection method. Once both pipes are secured by adapter fittings, wrap plumber’s tape around the end of the threaded male fitting to ensure the connection is watertight.
Using a Push-to-Connect Fitting
This is the fastest and simplest method to connect PVC to PEX pipe. You’ll first need to identify the pipe material used, select an appropriate transition fitting, and cut the pipe cleanly and squarely. SharkBite’s PVC transition coupling is designed to easily connect these two types of pipe. No glue is needed. The fitting is pushed into the pipe to an insertion mark that you make prior to connecting the pipes (the company makes a Depth & Deburr Gauge to measure where to mark the pipe).
Tips for Connecting Pipes
When the push fittings are inserted, just twist the pipe ends together to seal the line. To ensure a secure connection, and avoid a leak, keep the following in mind:
- There must be one male fitting and one female fitting for each connection.
- The threaded ends of each fitting must match exactly.
- Pipes of different sizes can be connected, but the threaded ends must be equal in size.
Contact Village Plumbing and Air for Help
We offer a full range of plumbing services in the Houston area. Our trained technicians can help repair, replace, or add pipe in your home. If you’re not comfortable attempting to connect PVC to PEX yourself, our experienced professionals can handle the job. In addition to quality service and workmanship, Village Plumbing offers a full warranty for installation work as well as financing and exclusive maintenance plans. Call 713-526-1491 to schedule service or learn more.