Steel casing pipe, also known as encasement pipe, is most commonly used in underground construction to protect utility lines of various types from getting damaged.  Such damage might occur due to the elements of nature or human activity.
Steel casing pipe is used in different types of horizontal underground boring, where the pipe is jacked into an augered hole in segments and then connected together by welding or by threaded and coupled ends, or other proprietary pipe connectors such as interference-fit interlocking push-on joints. The steel casing pipe can also be set up and welded into a "ribbon" and then directionally pulled through a previously drilled hole under highways, railroads, lakes and rivers.