Pex tubing is usually used for radiant heat installations. However, it is now being used more for hot and cold plumbing systems. Pex tubing is strong and flexible and can be used in hot and cold temperatures. It is expensive but worth the money if you can afford it because when using pex tubing, you will not have to worry about pipes freezing or busting during cold weather. Pex is also easy to install and resistant to chemicals found in the plumbing environment.
Measure the pex tubing you will need for the installation. Cut it with the tubing cutter. The tubing cutter is specially designed for pex tubing and should always be used for this type of installation. Put a copper crimp ring onto the pipe once it is cut to the length you need it.
Place the tubing into the pipe fitting. Make sure it bottoms out on the shoulder of the fitting. Slip the copper crimp ring up so that it is 1/8 to 1/4 inch away from the tubing.
Test the crimp ring with the gauge flow. The gauge flow will slide right onto the fitting easily. It might be tight since the crimping tool marked the surface during the crimping process. The gauge flow should not slide over the fitting. If this happens, you will have to do everything over again.
Inspect your work. It is extremely important that this is done correctly. If the ring is crimped over the tubing, then there are not enough ribs covered. If the crimp tool is not at 90 degrees, the plastic will be dented and there will not be enough rib coverage. If the copper crimping ring is not all the way covered by the crimping tool, then the ring will be twisted with a non crimp. Also, if the tubing is not cut squarely the tubing will not cover the ribs of the fitting properly. All of these can cause a leak hazard and a bad connection.
Run the next row of tubing. Put in your next fitting and repeat steps one through four for the rest of the pex plumbing.
Make a loop in the pex that is not more than 8 times the width of the tubing. The reason for this is because pex is installed different than PVC and copper pipe. Adjustments have to be made for pex for every -12.2 degrees C in temperature change. Pex will reduce one inch every 100 feet of pipe with every 10 degree of the temperature change.
Use straps and hangers when installing the pex plumbing because the pex will have to be supported every 32 inches if the tubing is installed along a joist. If installing the pex on top of a beam, support the pex every 6 feet. Always leave some slack in the tubing for contraction. Make sure the support hangers are not too tight as they will reduce movement of the pex.
Tips and warnings
- Use straps and hangers when installing the pex plumbing because the pex will have to be supported every 32 inches if the tubing is installed along a joist. If installing the pex on top of a beam, support the pex every 6 feet.
- Always leave some slack in the tubing for contraction.
- Make sure the support hangers are not too tight as they will reduce movement of the pex.