Introduction
Using PEX-A or Expansion PEX pipe is a fast, easy, and economical way to upgrade or retrofit your home water plumbing. In this guide we will go over the basics of installing PEX-A pipe.
Connecting to Existing Pipe
Copper Pipe to PEX-A
If the existing water pipe material is copper, several types of fittings can be used to connect PEX-A pipe. Sweat adapters such as Female Sweat – PEX-A or Male Sweat – PEX-A can be used to connect to existing copper pipe or at an existing fitting such as a valve or tee. Push-to-Connect adapters are a sweat-free way to also connect PEX-A to copper.
Iron Pipe to PEX-A
For connecting to galvanized iron pipe, threaded adapters will need to be used to connect PEX-A pipe. Female NPT – PEX-A adapters can be used to connect to threaded pipe ends and Male-NPT – PEX-A adapters can be used to connect to fittings such a valve or tee. Push-to-Connect adapters will not work with iron pipe.
CPVC to PEX-A
Connecting CPVC pipe with PEX-A pipe, Push-to-Connect fittings are the easiest method. CPVC – PEX-A fittings can also be used but require solvent welding to create a seal and can only be used once.
Polybutylene to PEX-A
While not as common as copper piping, polybutylene is easily distinguished from PEX piping by its grayish or bluish color. While polybutylene pipe uses insert fittings and compression rings, the fittings for PEX-A and polybutylene pipes are not interchangeable. Special transition or Polybutylene – PEX-A fittings should be used.
Installing PEX-A Pipe
First step in installing PEX-A pipe is measure the distance of pipe needed to connect from one fitting to the next. If bending the PEX-A pipe to go around obstacles or hard-to-reach places, add 6″ to the length for each bend.
Next cut the pipe square and remove any burrs from the cut end. Install the expansion sleeve over the cut pipe with the sleeve not overhanging more than 1/8″ over the cut end. Using the correct expansion head for the size of PEX-A pipe. Insert the expansion head uniformly into the pipe and ring and expand uniformly by rotating the head if using a manual expander.
Insert the fitting into the expanded pipe end and wait several minutes for the expanded pipe and sleeve to contract onto the fitting. Visually check the fitting to make sure that pipe is square and flush against the shoulder of the fitting. When water is turned on, check the fitting for leaks.
Further Information
For more information on PEX-A pipe and other piping systems for Kitchen and Bath, checkout out our other articles.