"Brian Reay" wrote in message
...
I'm trying to find the manufacturer of 'heavy duty' round plastic conduit-
ideally about 20 mm in diameter.
....

Anyone know the product?

Egatube high impact conduit heavy gauge, which is available in wall
thicknesses up to 2.5mm, although you may need to order a 30m carton if your
local MK Electrical stockist doesn't have that wall thickness in stock.

Colin Bignell