Pex pipe is a cross linked polyethylene product. This means that through the processes of manufacturing the molecules are made so they form bridges – thus the term ‘cross linked’. The resulting pipe is a strong flexible pipe that can handle extremes in temperature, from below freezing to 200 degrees Fahrenheit. Pex pipe is available through most plumbing wholesale distributors in the US and Canada. It is usually available in sizes up to one inch for most household plumbing uses, and can be bought in bigger diameters but it isn’t as readily available.
- Since pex is a flexible pipe, and is furnished in bulk length, stored wound around spools, rather than in straight length sections, it costs less to ship and store.
- Also, due it’s flexibility, fewer interconnections and fittings are required, since it can go around corners without using elbow fittings, so it’s easier to install.
- Corrosion and pitting are non-existant with pex, and unlike copper, it is highly resistant to scaling build-up.
- Pex is less prone to freeze-up breakage and transfers less heat than copper pipe, which makes it more energy efficient for hot-water use.
- Useful in hard to reach areas with limited access and visibility
- Presents lower resistance to water flow, good for low water pressure problems
Pex Connection Techniques
There are a couple of different connection methods for flexible plastic pex plumbing. The most commonly used is the copper crimping ring. This calls for a pex crimping tool to crimp the ring over the pipe and fitting.
The expansion connection method uses a tool to expand the pex tube’s diameter. Then you insert an expansion fitting into the expanded tube end, and then a plastic ring is pressed over the fitting , creating a secure connection. Other methods are compression fittings, and using a stainless steel clamp in combination with a nipple fitting.
Indoor Uses of Pex Pipe
Pex pipe can be used for most types of plumbing because of its ability to take temperatures ranging from below freezing to 200 degrees Fahrenheit. It is a good product to use in radiant heating applications. Radiant heating is when the heat source is contained in a floor instead of having registers and radiators. Pex pipe is flexible enough to use in the length needed without the need for junctions and elbows, making it a good choice for this type of heating system.
Pex pipe can be used in all other plumbing projects too. Because of its flexibility the installer can eliminate a lot of the joints and bends that have to be put in for regular PVC pipe to be used. The only problem with Pex pipe is that it may not have been approved for using in plumbing for houses in your area. You would have to check with the town’s building codes before using Pex pipe. Because of its flexibility, Pex pipe is quieter when used in heating systems and you won’t get pipe noise when it is heating up.
Outdoor Uses of Pex Pipe
Pex pipe is limited to underground uses now because it isn’t made to be exposed to the elements. It is excellent for water service underground. Irrigation systems that are underground and getting water where it is needed. Pex pipe can be cemented right into a slab without damage, this is one of the reasons it is good for radiant heat systems. Pex pipe would be a good choice for supplying water to campground sites where the pipes need to be able to withstand freezing without bursting in the winter months.
Pex pipe is a money saver if your building codes allow its use not only in price but in installation too since the flexibility of the pipe allows for less time putting together elbows and fittings for corners and bends in the pipe.
Pex pipe has been used in Europe for many years now and it is just gaining popularity in the U.S. As I said before, you need to check with local housing codes before using it in your house for plumbing.
Pex pipe has been used in millions of homes in the Midwest and so far there have been few problems with it, and these were with the installers. The idea of using Pex pipe for all plumbing needs is still under research and opinion to see if it is the best product for the job.
It would appear that Pex pipe is going to come out on top, not only for its durability but in the area of costs as well. Housing codes need to be update everywhere to allow the use of the pipe in homes all over the US, not just in a few places. Then we can all save some money and the time spent putting together stiff pipes can be better used in other areas of construction.
Photo by Jennifer Dickert, Creative Commons Attribution License