Tried replacing my leaking shutoff valve

[Jose1983]

I replaced my leaking shut off valve that supplies water to the restroom sink faucet. What kind of water pipe is this????? It looked aluminum in color. It also looks like PEX. I’m just a Homeowner trying to figure it out. Thanks

 

[Breplum]

It is PEX

 

[Sponsor]

 

[Reach4]

It looks like a compression valve over PEX. There was an insert in the PEX so that you could use the compression valve. You may be able to put on a new compression valve, using the old nut, ferrule, and insert.

 

[John Gayewski]

That's pex type A with a stiffener inserted.