Cast steel pipe, or ductile iron pipe, is a type of water pipe manufactured from cast iron, a metal with high durability and sturdy structure. Cast steel pipes are commonly used to convey drinking water, wastewater, rainwater, and various liquids in water supply and drainage systems for buildings, residential areas, and industrial applications.

The uses of cast steel pipes in the construction industry include:

1, Water Conveyance: Cast steel pipes are widely used for conveying clean water from the water supply source to buildings, factories, and other water usage locations. They are preferred in water supply systems due to the durability and load-bearing capacity of cast iron.

2. Wastewater Conveyance: Cast steel pipes are also used to convey wastewater from buildings and industrial areas to wastewater treatment systems. They can withstand pressure and the effects of sewage over extended periods.

3. Rainwater Drainage: In drainage systems, cast steel pipes can direct rainwater from roofs to the drainage system.

4. Industrial Applications: Cast steel pipes find applications in industrial processes, such as conveying gases, steam, and other liquids in manufacturing plants and factories.

The advantages of cast steel pipes include their durability, load-bearing, pressure resistance, heat resistance, and excellent corrosion resistance. However, they can be heavier and require more precise machining than other types of water pipes, like PVC pipes, and may demand particular installation and maintenance processes.