Pex-Al-Pex Bend Radius

[Onoff]

I've found a generic spec for Pex-Al-Pex UFH pipe that states the minimum bend radius as >=5D. So with a 16mm pipe it's r80mm. Is that rad to the inside, outside or centreline of the pipe does anyone know? Cheers.

[Nickfromwales]

Id say inside .