What Is a Steel Casing Pipe?  Steel casing is type of pipe that typically runs underground. It can be used to protect items inside the pipe or to provide an extra barrier between the matter in the pipe and the earth. Another name for these products is encasement pipes. The pipes are usually placed in the ground in separate segments and then welded together. In some cases, pipe can be threaded through a pre-existing hole or tunnel. The latter method is usually necessary because the hole was drilled, rather than dug from ground level, due to an obstruction such as a road or a river. Steel casing pipe comes in a wide array of sizes and grades. It is categorized by both the diameter of the pipe interior and the thickness of the pipe walls. Many grade descriptions begin with the prefix ASTM, which stands for the American Society for Testing Materials. The ASTM is an international organization that sets standards for a wide array of building materials, including pipes. There are some locations where an ASTM grade is a legal requirement for construction materials.

The most commonly used type of steel casing pipe is ASTM A-252. It is desirable for many builders because it tends to be a cost effective grade of pipe that does not require as strict adherence to inspection requirements as many other grades of pipe. For example, ASTM A-252 does not need hydrostatic testing, which is a method used to find the source of leaks.
A steel casing pipe will often be used to provide protection for or serve as an extra barrier around liquid that is being transported. It can help to prevent the contamination of water from outside elements. The pipe can also keep fuels such as oil and gas from leaking into the soil.
Protection of a wide array of underground lines and cables is another use for steel casing pipe. They can encase utility lines or help to protect electrical or fiber optic cables. Often, several different types of cables or lines will be put in the same network of pipes.
When multiple lines share a steel casing pipe, they are usually attached to the side of the pipe with casing spacers. This helps keep the lines separate. The spacers are usually made of steel or plastic, and each end of the pipe is usually protected with seals made of pliable material, such as rubber.

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