is ALL grey piping poly?

[bmargiotti]

well is it??

[Harold E. Miller]

http://www.polybutylene.com/poly.html

[Doug Edwards, CMI]

No. Some PB is not gray, Ive seen it in bright blue as well, normally for the main coming in from the street / meter. Some PEX is gray also only a lighter gray. Will often have "Merflex" stamped on it.

[Harold E. Miller]

Doug...it is true that PB can be other colors than gray. (white, black, and blue)
But I think what Bob was trying to find out is if all gray plumbing is PB.
In my experience all gray plumbing I have ever seen is PB. For instance I have never seen gray polyethelene, or gray PEX,
...but I haven't see everything yet.