What is cast iron or ductile iron pipe primarily used for?

Cast iron or ductile iron pipe is primarily used for underground water supply and drainage due to its durability, resistance to corrosion, and ability to withstand high pressure and heavy loads. These materials have been a long-standing choice for water transportation because they can handle the rigors of being buried underground, where they face various soil conditions and potential physical impacts from surface loads. Additionally, cast iron has excellent tensile strength, making it suitable for water mains and sewer systems, where structural integrity over time is crucial.

While there are applications for cast iron and ductile iron pipes in heating systems, air distribution systems, and high-pressure gas lines, these are less common compared to their use in water supply and drainage. Cast iron pipes are more suited for the conditions of underground installations, where their properties ensure longevity and reliability in conveying water and managing drainage effectively.