I can't get to sleep so I thought I would make a post about something I get asked about a lot.
There seems to be a lot of confusion about pex sizes. Places selling it and claiming true 1" ID or something similar and claiming normal pex is the listed as the OD only make it worse. The biggest problem I have with listing it that way is that it makes finding the correct fittings a nightmare and a lot of people end up with improper fittings or just use hose barbs and clamps.
This post is to try to explain it.
All normal pex is copper tubing size (CTS). This means the outside diameter is the same as copper pipe. 1" copper pipe is 1-1/8" OD and so is pex. Normal pex uses the SDR9 standard which means that the wall thickness is 1/9 that of the diameter. Fittings for this pipe are available almost everywhere.
The pex that most people call true 1" ID is actually metric. I have seen it listed 2 ways and I am not sure if there are 2 standards. One way is by both ID and OD. What a lot of people claim as 1" ID is 26mm / 32mm. I have also seen pex listed as nominal size which is a measurement from the center of one wall to the center of the other.
Pex al pex usually is metric also but rarely advertised that way. That doesn't bug me as much though because it uses different fittings and doesn't cause confusion.
If anyone has anything to add or corrections to anything I said, please post them.
Author
Topic: Pex (Read 2527 times)