Question: Many operators have pre-defined segments on their pipeline (e.g., the length of pipe between two compressor stations or between consecutive isolation valves is considered a segment). When OPS refers to segments in HCAs in the rule, in what context is the term segment used?
Answer: As used in the rule "covered segment" means a continuous segment of pipeline located in an HCA. If the potential impact circle methodology is used to identify HCAs, then, at a minimum, the covered segment begins at the outermost edge of the first potential impact circle that meets the HCA criteria and extends axially to the outermost edge of the last contiguous potential impact circle that meets the HCA criteria. This length of pipe may be subdivided to facilitate integrity assessments. Examples include such divisions as pressure limiting stations, pipe size changes or other practical divisions.