NEN ISO 21004 : 2006

Defines the general requirements and the performance requirements for multilayer pipes based on thermoplastics intended to be used for water supply outside buildings, for buried water mains and services and for water supplies above ground. It also gives guidance for the design of piping systems consisting of multilayer pipes based on thermoplastics or, for which at least 60% of the wall thickness is polymeric material, and the inner layer in contact with water is made of polymeric material.