[1] ISO 161-1:1996

Thermoplastics pipes for the conveyance of fluids - Nominal outside diameters and nominal pressures - Part 1: Metric series

[2] ISO 497:1973

Guide to the choice of series of preferred numbers and of series containing more rounded values of preferred numbers

ISO 2944:1974

Fluids power systems and components - Nominal pressures

ISO 3126:1974

Plastics pipes - Measurement of dimentions

ISO 11922-1:1997

Thermoplastics pipes for the conveyance of fluids - Dimensions and tolerances - Part 1: Metric series