Cast iron pipes were typically used for which type of piping?

• A. Sewer or drainage
• B. Water supply lines
• C. Gas lines
• D. Heating lines

Answer: (A)

Cast iron pipes are chosen for sewer and drainage systems because they are extremely strong under soil loads and durable when buried. Their heavy wall and rigid construction resist crushing and movement in the ground, and they can be jointed tightly to minimize infiltration and exfiltration over long runs. This combination makes cast iron a reliable, long-lasting choice for underground waste lines. For other applications, different materials are typically used: water supply lines more commonly use copper, PVC, or ductile iron for better flexibility and corrosion resistance; gas lines and heating lines rely on materials like steel or other metals designed for those specific safety and pressure requirements. So the primary use that aligns with cast iron’s properties is sewer or drainage.