This appraisal is for DN 100 and DN 150 ANT ductile iron polymeric coated backing rings for use with polyethylene (PE) flanges.
The PN16 backing rings conform to the dimensional and mating dimensions of AS/NZS 4087:2011 Flanges for water supply applications with internal diameters conforming to ISO 9624:2019 Thermoplastics piping systems for fluids under pressure - Flange adapters and loose backing flanges-Mating dimensions.
Backing rings for use with PE flanges have traditionally been manufactured from galvanised mild steel or stainless steel. Ductile iron backing rings offer a technically equivalent and competitive alternative.