How to Use PEX Tubing for Residential Plumbing
Install Water Supply for Kitchen or Bathroom Remodel Projects
Mar 3, 2009
In the late 1950s, chemical engineers and scientists labored to develop a material to modify the polymer chains in polyethylene so that it wouldn't soften as the temperature rises.
This led to the development of PEX in the 1960s. It remains strong and flexible from temperatures below freezing to 200 degrees F (93.3 degrees Celsius). This characteristic makes it ideal for use in home plumbing systems where the temperatures vary by climate and water temperature.
The Benefits of Plumbing with PEX Tubing
- As mentioned above, due to its molecular structure, it remains stable as the temperature changes. Expansion and contraction is a major problem when trying to connect PVC to copper or galvanized pipe. PEX minimizes this issue.
- The tubing is flexible. This makes it much easier to work with since it eliminates threading metal pipe and gluing PVC fittings every time a corner must be made and can improve water flow by eliminating hard corners. This also lowers labor installation costs.
- It takes the guesswork out of distinguishing between hot and cold water supply lines. With this color-coded material, blue equals cold and red equals hot.
- The interior will not corrode, unlike copper and galvanized, which requires plumbing repiping or epoxy-coating plumbing pipes.
- It's compatible with existing metal pipe when making repairs, retrofits, or adding capacity during a remodel or room addition.
Components Used in PEX Installation
- In-line fittings – Used to add a shut-off valve or to connect two lengths of tubing.
- Push-fit fittings – Utilizes metal tines to secure the tubing to tubing or tubing to copper line tight against O-ring seals.
- Clamp-ring connections – Used to connect existing metal pipe to tubing, making it very handy for repairs or a retrofit project. The connection has a male end and a female end. The tubing is crimped onto the male end. The female end may be either soldered to the pipe or threaded on it.
- Manifolds – Manifolds operate in a manner similar to shower and bathtub hot/cold water mixing manifolds, except that with PEX manifolds have one input and more than one output for the same temperature water. One tube supplies the manifold and two or more tubes branch out on the output side. This is handy for kitchen or bathroom remodeling projects. The more expensive manifolds are sometimes equipped with shutoff valves.
- Rolls of PEX tubing – Depending on manufacturer, it's available in rolled lengths of up to 1000' which makes it easy to transport to the work site. For smaller jobs, straight lengths of up to 20' are available. Tube sizes vary from 1/4” to 1” CTS (Copper Tube Size).
Tools Used During Installation
The tool list is not too extensive. For cutting the tube, use a tubing cutter to ensure a clean cut end. A PVC cutter is all that's needed. Other than that, what's needed depends on the type of connection being made.
Use a clamp-ring crimping tool when making a clamp-ring connection or using an in-line fitting. If one end is copper pipe, solder, flux, and a small torch will be needed.
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