255.933 Addressing integrity issues.

An operator must take prompt action to address all anomalous conditions that the operator discovers through the integrity assessment. In addressing all conditions, an operator must evaluate all anomalous conditions and remediate those that could reduce a pipeline's integrity. An operator must be able to demonstrate that the remediation of the condition will ensure that the condition is unlikely to pose a threat to the integrity of the pipeline until the next reassessment of the covered segment. If an operator is unable to respond within the time limits for certain conditions specified in this section, the operator must temporarily reduce the operating pressure of the pipeline or take other action that ensures the safety of the covered segment. If pressure is reduced, an operator must determine the temporary reduction in operating pressure using ASME/ANSI B31G (as described in section 10.3 of this Title) Pipeline Research Council, International, PR-3-805 ("RSTRENG"; as described in section 10.3 of this Title) or reduce the operating pressure to a level not exceeding 80 percent of the level at the time the condition was discovered. A reduction in operating pressure cannot exceed 365 days without an operator providing a technical justification that the continued pressure restriction will not jeopardize the integrity of the pipeline.#

Discovery of a condition occurs when an operator has adequate information about a condition to determine that the condition presents a potential threat to the integrity of the pipeline. A condition that presents a potential threat includes, but is not limited to, those conditions that require remediation or monitoring listed under paragraphs (d)(1) through (3) of this section. An operator must promptly, but no later than 180 days after conducting an integrity assessment, obtain sufficient information about a condition to make that determination, unless the operator demonstrates that the 180-day period is impracticable.#

An operator must complete remediation of a condition according to a schedule that prioritizes the conditions for evaluation and remediation. Unless a special requirement for remediating certain conditions applies, as provided in subdivision (d) of this section, an operator must follow the schedule in ASME/ANSI B31.8S (as described in section 10.3 of this Title), section 7, Figure 4. If an operator cannot meet the schedule for any condition, the operator must justify the reasons why it cannot meet the schedule and that the changed schedule will not jeopardize public safety. An operator must notify the department and OPS in accordance with section 255.949 of this Part if it cannot meet the schedule and cannot provide safety through a temporary reduction in operating pressure or other action.#

(1)Immediate repair conditions. An operator's evaluation and remediation schedule must follow ASME/ANSI B31.8S, section 7 in providing for immediate repair conditions. To maintain safety, an operator must temporarily reduce operating pressure in accordance with subdivision (a) of this section or shut down the pipeline until the operator completes the repair of these conditions. An operator must treat the following conditions as immediate repair conditions:#

(i)a calculation of the remaining strength of the pipe shows a predicted failure pressure less than or equal to 1.1 times the maximum allowable operating pressure at the location of the anomaly. Suitable remaining strength calculation methods include, ASME/ANSI B31G; PRCI PR-3-805 (RSTRENG); or an alternative equivalent method of remaining strength calculation. These documents are incorporated by reference and available at the addresses listed in section 10.3 of this Title;#

(ii)a dent that has any indication of metal loss, cracking or a stress riser;#

(iii)an indication or anomaly that in the judgment of the person designated by the operator to evaluate the assessment results requires immediate action.#

(2)One-year conditions. Except for conditions listed in paragraphs (1) and (3) of this subdivision, an operator must remediate any of the following within one year of discovery of the condition:#

(i)A smooth dent located between the 8 o'clock and 4 o'clock positions (upper 2/3 of the pipe) with a depth greater than six percent of the pipeline diameter (greater than 0.50 inch [13 millimeters] in depth for a pipeline diameter less than Nominal Pipe Size [NPS] 12).#

(ii)A dent with a depth greater than a two percent of the pipeline's diameter (0.250 [6 millimeters] inch in depth for a pipeline diameter less than NPS 12) that affects pipe curvature at a girth weld or at a longitudinal seam weld.#

(3)Monitored conditions. An operator does not have to schedule the following conditions for remediation, but must record and monitor the conditions during subsequent risk assessments and integrity assessments for any change that may require remediation:#

(i)A dent with a depth greater than six percent of the pipeline diameter (greater than 0.50 inch [13 millimeters] in depth for a pipeline diameter less than NPS 12) located between the 4 o'clock position and the 8 o'clock position (bottom ⅓ of the pipe).#

(ii)A dent located between the 8 o'clock and 4 o'clock positions (upper 2/3 of the pipe) with a depth greater than six percent of the pipeline diameter (greater than 0.50 inch [13 millimeters] in depth for a pipeline diameter less than nominal/pipe/size [NPS] 12), and engineering analyses of the dent demonstrate critical strain levels are not exceeded.#

(iii)A dent with a depth greater than two percent of the pipeline's diameter (0.250 inch [6 millimeters] depth for a pipeline diameter less than NPS 12) that affects pipe curvature at a girth weld or a longitudinal seam weld, and engineering analyses of the dent and girth or seam weld demonstrate critical strain levels are not exceeded. These analyses must consider weld properties.#