... with the following nominal sizes and tolerances: Outside diameter mmWall thickness mmNominal) Min. MaxNominal Min. Max.12 12,0 12.31,1 1.1 1 ... .416 16,0 16,31,5 1,5 1,816 16,0 16,31,8 1,8 2,120 20,0 20 ... the dimensions of the pipe. 2. Multilayer pipes manufactured according to UNE-EN-ISO 21003 with the following nominal sizes and tolerances ...