255.937 Continual process of evaluation and assessment.

After completing the baseline integrity assessment of a covered segment, an operator must continue to assess the line pipe of that segment at the intervals specified in section 255.939 of this Part and periodically evaluate the integrity of each covered pipeline segment as provided in subdivision (b) of this section. An operator must reassess a covered segment on which a prior assessment is credited as a baseline under section 255.921(e) of this Part by no later than December 17, 2009. An operator must reassess a covered segment on which a baseline assessment is conducted during the baseline period specified in section 255.921(d) of this Part by no later than seven years after the baseline assessment of that covered segment unless the evaluation under subdivision (b) of this section indicates earlier reassessment.#

An operator must conduct a periodic evaluation as frequently as needed to assure the integrity of each covered segment. The periodic evaluation must be based on a data integration and risk assessment of the entire pipeline as specified in section 255.917 of this Part. For plastic transmission pipelines, the periodic evaluation is based on the threat analysis specified in section 255.917(d) of this Part. For all other transmission pipelines, the evaluation must consider the past and present integrity assessment results, data integration and risk assessment information (section 255.917 of this Part), and decisions about remediation (section 255.933 of this Part) and additional preventive and mitigative actions (section 255.935 of this Part). An operator must use the results from this evaluation to identify the threats specific to each covered segment and the risk represented by these threats.#

In conducting the integrity reassessment, an operator must assess the integrity of the line pipe in the covered segment by any of the following methods as appropriate for the threats to which the covered segment is susceptible (see section 255.917 of this Part), or by confirmatory direct assessment under the conditions specified in section 255.931 of this Part.#

(1)Internal inspection tool or tools capable of detecting corrosion, and any other threats to which the covered segment is susceptible. An operator must follow ASME/ANSI B31.8S (as described in section 10.3 of this Title), section 6.2 in selecting the appropriate internal inspection tools for the covered segment.#

(2)Pressure test conducted in accordance with the testing requirements of this Part. An operator must use the test pressures specified in table 3 of section 5 of ASME/ANSI B31.8S, to justify an extended reassessment interval in accordance with section 255.939 of this Part.#

(3)Direct assessment to address threats of external corrosion, internal corrosion, or stress corrosion cracking. An operator must conduct the direct assessment in accordance with the requirements listed in section 255.923 of this Part and with as applicable, the requirements specified in section 255.925, 255.927 or 255.929 of this Part.#

(4)Other technology that an operator demonstrates can provide an equivalent understanding of the condition of the line pipe. An operator choosing this option must notify the department and OPS 180 days before conducting the assessment, in accordance with section 255.949 of this Part.#

(5)Confirmatory direct assessment when used on a covered segment that is scheduled for reassessment at a period longer than seven years. An operator using this reassessment method must comply with section 255.931 of this Part.#