ISO 8179-1:2017 specifies an external protective coating system which is factory applied to ductile iron pipeline components as specified in ISO 2531, ISO 7186 and ISO 16631. This coating system comprises an electro-deposited metallic zinc-based coating of
- pure metallic zinc with a purity of 99,99 %,
- zinc and aluminium alloy with or without other metals, or
- other zinc alloys
followed by a finishing layer that can be bituminous paint or synthetic resin compatible with zinc-based coating.
NOTE ISO 8179-2 deals with zinc-rich paint coating.