Cast iron pipes are pipe materials primarily manufactured from ductile cast iron using the centrifugal casting method (spinning casting). This manufacturing method results in a uniform wall thickness and a dense structure, achieving high pressure resistance, corrosion resistance, and durability. Ductile cast iron pipes, in particular, are widely adopted as water and gas transmission and distribution pipes in critical infrastructure such as water supply and sewerage, gas, and industrial water, due to their excellent mechanical strength and toughness. The inner surface is treated with mortar lining or epoxy resin coating, and the outer surface with zinc spraying and epoxy resin coating, to ensure long-term corrosion protection. Mechanical joints and flange joints are used for connection, with consideration given to ease of installation.