casing pipe is a type of steel pipe that is typically used to enclose and surround a carrier pipe, which is installed through the center of this pipe. steel casing pipe is most often used in underground construction projects to encase or protect utility lines from being damaged. this pipe can be used when boring horizontally or directionally under roads, rivers, lakes, or railroads. in general, steel casing pipe is extremely durable and versatile, and therefore, it can be used in a variety of construction projects as well. casing pipe is available in a complete variety of different sizes and diameters as well as in straight seam, spiral-weld, and rolled and welded types of manufacture.