There is PEX "a" , "B" and "c"

To Do It Yourself Plumbers (like me):

Be Aware: Pex tubing is not all the same!

Pex has become very popular because it is easier to work with than copper and is resistant to breaking if it freezes. The latter is a very important charactaristic here in the North.

There is PEX "a" , "b" and "c". A is only made by Wirsbo and Rahau. Most others are "b". A and B are ok for regular domestic water. A has a few advantages for strength way beyond residential use though. Type A needs special $600 tool and special connecting inserts. Each type has it's own fittings and tools and they are not interchangable with the exception of some new compression style fittings that I have heard can be used on any type (those fittings are more expensive).

www.rehau-na.com

They all come in different colors. The colors make no difference as far as the type or use of pex. The different colors are just so you can use a different color for different lines if you want to. For example, you could use blue for cold water and red for hot water, but the tubes are the same other than the color.

Zern brand pex and all of the fittings and tools are sold at Home Depot and Lowe's and are much less expensive than Wirsbo. I have chosen to use Zern for those reasons. Should have a gauge for quality control. Also, for about $25 you could buy a Zern pex ring clamp cutting tool to remove and redo badly crimped rings. It happens.

Zern pex QP3C100 – is regular (not oxygen barrier). It is important to use oxygen barrier pipe only if some part of the system is in contact with ferrous (iron-containing) metal such as a boiler (apparently) – do not know, but it may also be important for running glycol regardless if it contacts ferrous metal or not. If you are using the pex in your heating system then make sure you are using the oxygen barrier (more expensive) version of whatever type you choose to use.

Zern is type b pex. Zern crimp rings and barbed fittings will not work on type A pex. Type b Zern brand pex comes in regular and oxygen barrier -- both can be different colors (blue, red, white).

www.zernpex.com

Lowes Spring 2008:

100 ft. regular Zern pex 1/2” $28.57

100 ft. oxygen barrier Zern pex 1/2” $50.57

So, to get started, you need to figure out the size and length of tubing that you will use. If you choose Zern brand then you need a seperate crimping tool (about $90) for each size as well as rings, fittings, gauge, and crimp ring removal tool.

Frank Cook

May 2008