PEX Tubing

PEX plumbing was developed in the 1960s and is more formally called 'cross-linked polyethylene'. Although an old technology it is only recently being used in U.S. plumbing. A popular application of PEX tubing is in radiant heat systems.

Unlike copper, PEX tubing is made from flexible plastic called polyethylene that is strengthened through a special process using fancy checmicals. This product has been swiftly gaining popularity to serve as a supply pipe for plumbing use in residential areas. The piping is able to withstand a wide temperature range all the way from subfreezing to 180 degrees F. Installing PEX piping is simpler than copper and this significantly reduces the overall cost of installation. Another benefit is that PEX tubing is quieter than the fixed pipe systems traditionally used. PEX connections are much simpler than soldering or gluing fixed pipe and can bend around corners reducing the need for joints which is where most piping eventually fails. It is used world-wide for heated drive ways or sidewalks to melt snow in adition to many other radiant heat applications.

PEX can be used ideally in hot as well as in cold water systems. It is also used in ice skating rinks and refrigeration warehouses. Ultimtely check with your local authority as not all building code have been updated to allow PEX to be used. One application that PEX can not be used for is in above ground system as it is not UV protected and can withstand direct sunlight.

Another big benefit of PEX is there are fewer fittings to work with making it simpler and easier to use. A great deal of plumbing problems will occur at the joints. Thankfully, PEX's flexibility enables it to have fewer joints.

On To Installing PEX Tubing

PEX uses a crimp-ring/compression system. That is how you get your sealed connection as opposed to using a glue or soldering. Strong brass fittings are put into one end of the PEX pipe. Now make use of a crimp tool that has a positive interlocking jaw action, then crimp a copper ring onto the pipe.

Necessary Tools

You should have the following tools on hand:

- Full-circle crimping tool
- Utility knife
- Copper manifolds
- PEX crimp fittings
- Shutoff valves
- Flexible tubing cutter
- Go/Go-go gauge
- PEX supply pipe
- Transition fittings
- Copper and plastic hangers

Connecting Pipes

- First you measure and cut the tubing to length. Be careful to not create any burrs (having a high quality cutting too will avoid this). Ineffective tools cause improper connections.
- Place the crimp-ring onto the piping. Do NOT use a hose clamp.
- Slide the fitting into the pipe up to the fitting's shoulder.
- Slide the crimp-ring roughly 1/8" to 1/4" from the end of the pipe. Outside of that range can cause a weak connection resulting in leakage.
- The last step is to use the crimping tool to compress the ring onto the tubing. It is important to maintain a 90 degree angle and ensure a completely closed crimp-ring.

The beauty of PEX tubing is that it can be installed, reapaired and maintained by the homeowner much more easily than fixed-pipe can be. Be sure to use quality tools that are in very good condition so that you will have an efficient end result.

Don't Forget To Inspect

When you are done you must inspect all joint work. It is quite important that you finish the joint job correctly. When you are inspecting look for these things:

- A proper crimp at each tube's ends.
- Not enough ribs are covered.
- The crimp tool was not at 90 degrees to the piping.. The piping wil have been dented and the ribs not completely covered
- Signs that the crimp-ring was not properly covered by the crimping tool. The ring is distorted with a crimp that is not uniform.
- All tubing has been squrely cut. Fitting ribs will be exposed.