scope:

Steel casings are used to install and maintain pipeline crossings such as those at road and railroad rights of way. This standard details acceptable practices for the design, fabrication, installation, and maintenance of steel-cased pipelines.

Use of cased crossings should be avoided unless required by load considerations, unstable soil conditions, or when their use is dictated by sound engineering practices.

This standard does not imply that utilization of casings is mandatory or necessary.

This standard does not imply that cased crossings, whether electrically isolated or electrically shorted, contribute to corrosion of a carrier pipe within a cased crossing. However, cased crossings may adversely affect the integrity of the carrier pipe by shielding CP current to the pipe or reducing the CP effectiveness on the pipe in the vicinity of the casing.

The practices contained in this standard may or may not be applicable to casings installed prior to its issuance. It is presumed that all practices described in this standard are performed in a safe manner.