This part of ISO 7628 lays down the dimensions and marking for thermoplastic tubings for use in air braking systems on road vehicles. ISO 7628/2 deals with installation on the vehicle and test requirements.
SIS SS-ISO 7628/1:1986 history
1986SIS SS-ISO 7628/1:1986 Road vehicles - Thermoplastic tubing for use in air braking systems - Part 1: Dimensions and marking