This document specifies the requirements and test methods applicable to factory applied internal lining made of thermoplastic acid modified polyolefin (TMPO) for the heavy duty corrosion protection of ductile iron pipes conforming to EN 545, EN 598 and EN 969. This document also applies to pipes with only socket and spigot ends coated with TMPO. Fittings and accessories are covered separately by EN 14901-2.