State where the following types of pipes are used: cast iron.

Cast iron pipes are commonly used in plumbing systems for drainage and sewer lines. They are also used in some industrial applications for transporting water, gas, and other fluids.

- Sanitary drainage and vent systems in commercial and industrial buildings.
- Storm drainage systems for conveying rainwater runoff.
- Sewer lines for transporting wastewater to treatment plants.
- Industrial piping for conveying corrosive or abrasive fluids.
- Fire protection systems for supplying water to sprinklers.