text: In Europe and Australia, ductile iron pipe is typically manufactured with a zinc coating overlaid by either a bituminous, polymeric, or epoxy finishing layer. EN 545/598 mandates a minimum zinc content of 200 g/m (at 99.99% purity) and a minimum average finishing layer thickness of 70 μm (with local minimum of 50 μm). AS/NZS 2280 mandates a minimum zinc content of 200 g/m (with a local minimum of 180 g/m at 99.99% purity) and a minimum average finishing layer thickness of 80 μm.
  No current AWWA standards are available for bonded coatings (zinc, coal tar epoxy, tape-wrap systems as seen on steel pipe) for ductile iron pipe, DIPRA does not endorse bonded coatings, and AWWA M41 generally views them unfavourably, recommending they be used only in conjunction with cathodic protection.