Ductile iron pipe

Ductile iron pipe is a modern evolution of cast iron, alloyed with magnesium to produce spheroidal graphite structures that give the material greater flexibility under load. It is widely specified for adopted sewer rising mains, large diameter trunk mains and pumped drainage in Thames Water infrastructure, manufactured to BS EN 598 for sewerage and BS EN 545 for water. Pipes are typically supplied with mechanical joints or push-fit gaskets and internal cement-mortar linings to resist sewage corrosion. Ductile iron is identifiable by its smooth grey-painted exterior and standardised flange or socket profile. While unlikely to be encountered on domestic drainage, the material is regularly cited in London new-build infrastructure specifications and section 104 agreements where pumped foul flows are required to cross uneven topography.