This part of ISO 17467 specifies the physical and mechanical properties of pipes made from unplasticized polyamide (PA-U) in accordance with Part 1, intended to be buried and used for the supply of gaseous fuels for maximum operating pressure up to and including 4 bar. It also specifies the test parameters for the test methods to which it refers. In addition, this part of ISO 17467 lays down dimensional characteristics and requirements for the marking of pipes.