Is the quoted diameter for flexible steel conduit the internal or external diameter? Or is it a sort of nominal diameter which cannot be measured?


Simply I am looking to protect a MDPE water supply pipe beneath a suspended floor from whatever may live under there - putting a Lidl endoscope through a hole found a dead rat..


What has come to mind is flexible steel conduit, MDPE water pipe is 25mm outside diameter, so would certainly fit inside 40 mm flexible steel conduit, but would it go through 32 mm conduit?  It is only the last 2 or 3 metres which will need protecting. The ends will be sealed, especially in the case of if I had to use 40mm.

Thanks.


Clive