On the market at present is a blue plastic 12x7mm bore pipe which is sold as a Cavis Benz substitute.
I have bought this pipe and fitted to a few Fulvias.
The other day I was investigating a (zero) fuel delivery issue on a 1600 which looked like pump problem. Changing the pump (actually it had an electric priming pump which was also swapped out) did not cure the problem. nor did bypassing the regulator or the in line filter - which was very clean. All the plastic fuel pipes were recently fitted, but one length had an obstruction which an air line could not blow through. From the outside nothing looked wrong but clearly (manufacturing fault?) the (ethanol resistant) plastic had formed an internal wall. It is strange as the car ran fine for 500km from fitting.
Has any one else had a problem with this blue pipe or was this hopefully a one off?