Is this PB(polybutylene) or PEX plumbing???

Need a little bit of help have a house with blue plumbing coming out of the slab. Looked all over but there is no lettering what so ever to give me any indication one way or another if its PB or pex. Looked through attic and other location the rest is copper. Anyone know if its pex or pb or know of a way to test it? The fitting doesn’t look like the standard fitting for PB not sure.

greyish blue? how old is the home?

The home was built in 1993/94 the main has an inspection tag dated september 1994. Not really greyish blue more along the lines of a darker blue

It was built in 93/94. The water main has an inspection date of 09/14. Its not blueish gray but more a dark blue

Factory built main water lines have no issues even if it is PB anyways.

Kevin any chance i can get a letter from you personally signing off on that

Looks like pex to me. That connector is for pex.

Agreed but I would not confirm it as PEX without seeing the stamp on the brass fitting.

The brass fitting is stamped MCD

Low quality fitting however we do not have this one in SSM.

You can’t be more incorrect. PB main water lines were bursting all over the country.

And yes, PB can be blue.

I have never heard of this at least not yet on the main in SSM On.
I have heard about many on the fittings.
So it is not an issue here.

Can you provide the link for my files so I can watch for this.

Looks like Big Blue

None of those you provided are correct as to what is displayed.

I agree Steve.

The most effective way of identifying polybutylene pipe is to have your plumbing inspected by a licensed professional. While inspectors generally cannot determine if there is deterioration in poly piping, licensed plumbers can confirm if you have poly piping installed in your home. Typical characteristics of polubutylene piping include:


  • Blue, gray, or black color
  • ½" to 1" diameter

[/LIST]Poly piping can be used anywhere in the home’s plumbing system – usually its presence can be ascertained by checking the attachments under household sinks, near hot water heaters, or leading into toilets. Following is a list of common places you may inspect for the presence of poly piping:


  • Entering the water heater
  • Crossing basement ceilings
  • Feeding sinks, toilets, and bathtubs



  • Entering the home through basement walls, etc
  • Attached to your home’s main water shutoff valve
  • Attached to your home’s water meter (often a copper pipe at a water meter will be attached to poly pipe somewhere underground, so it is wise to check both ends of the pipe)


Factory built main water line not a make shift poly or pex. At least that is what I see in the picture.
Here is the right up now that I am back in the office.
PE (Polyethylene) plastic is black or bluish flexible pipe sometimes used for main water lines as well as irrigation systems.
Now to further add to this it can be purchased with the threaded end female or male to connect to the copper lines. In most cases the fitting is stamped with the info written on it and the pipe has nothing. I am not saying it is PB, PE or PEX without seeing the writing on the union.
The manufacturer of the union is MCD and is ANSI approved.

Upon further investigation the fitting has CTS stamped to it not sure it that means anything or not.

Copper tube size!
This might help also