§ 192.611 — Change In Class Location: Confirmation Or Revision Of Maximum Allowable Operating Pressure

(a) If the hoop stress corresponding to the established maximum allowable operating pressure of a segment of pipeline is not commensurate with the present class location, and the segment is in satisfactory physical condition, the maximum allowable operating pressure of that segment of pipeline must be confirmed or revised according to one of the following requirements:

(1) If the segment involved has been previously tested in place for a period of not less than 8 hours:

(i) The maximum allowable operating pressure is 0.8 times the test pressure in Class 2 locations, 0.667 times the test pressure in Class 3 locations, or 0.555 times the test pressure in Class 4 locations. The corresponding hoop stress may not exceed 72 percent of the SMYS of the pipe in Class 2 locations, 60 percent of SMYS in Class 3 locations, or 50 percent of SMYS in Class 4 locations.

(ii) The alternative maximum allowable operating pressure is 0.8 times the test pressure in Class 2 locations and 0.667 times the test pressure in Class 3 locations. For pipelines operating at alternative maximum allowable pressure per § 192.620, the corresponding hoop stress may not exceed 80 percent of the SMYS of the pipe in Class 2 locations and 67 percent of SMYS in Class 3 locations.

(2) The maximum allowable operating pressure of the segment involved must be reduced so that the corresponding hoop stress is not more than that allowed by this part for new segments of pipelines in the existing class location.

(3) The segment involved must be tested in accordance with the applicable requirements of subpart J of this part, and its maximum allowable operating pressure must then be established according to the following criteria:

(i) The maximum allowable operating pressure after the requalification test is 0.8 times the test pressure for Class 2 locations, 0.667 times the test pressure for Class 3 locations, and 0.555 times the test pressure for Class 4 locations.

(ii) The corresponding hoop stress may not exceed 72 percent of the SMYS of the pipe in Class 2 locations, 60 percent of SMYS in Class 3 locations, or 50 percent of SMYS in Class 4 locations.

(iii) For pipeline operating at an alternative maximum allowable operating pressure per § 192.620, the alternative maximum allowable operating pressure after the requalification test is 0.8 times the test pressure for Class 2 locations and 0.667 times the test pressure for Class 3 locations. The corresponding hoop stress may not exceed 80 percent of the SMYS of the pipe in Class 2 locations and 67 percent of SMYS in Class 3 locations.

(4) The maximum allowable operating pressure of an eligible Class 3 segment may be confirmed by complying with the integrity management requirements in subpart O of this part and the additional or more stringent requirements in paragraphs (a)(4)(i) and (ii) of this section:

(i) By no later than March 16, 2028, or within 24 months of the date of the class location change, whichever is later, the operator must complete the following initial programmatic requirements:

(A) Conduct a baseline assessment of the eligible Class 3 inspection area and remediate all immediate and one-year conditions in accordance with this section and subpart O of this part. A prior assessment conducted after March 16, 2024, or within 24 months of the class location change, whichever is later, may be used as the baseline assessment. In addition, if the eligible Class 3 segment contains pipe with a seam formed by direct current electric resistance welding, low-frequency electric resistance welding, or electric flash welding, the assessment technology or technologies selected must have a proven application capable of assessing seam integrity and seam corrosion anomalies.

(B) Test the eligible Class 3 segment in accordance with the requirements in subpart J of this part to a pressure of at least 1.25 times the maximum allowable operating pressure. The results of a prior test, conducted for a duration consistent with the requirements in subpart J to a pressure of at least 1.25 the maximum allowable operating pressure, may be used to satisfy this requirement.

(C) Confirm that the eligible Class 3 segment has traceable, verifiable, and complete records available for pipe diameter, wall thickness, grade, seam type, yield strength, and tensile strength; or obtain the necessary material records in accordance with § 192.607.

(D) Install, or use existing, valves such that rupture-mitigation valves are located on both sides of the eligible Class 3 segment. Isolation valves on any crossover or lateral pipe designed to isolate a leak or rupture within the eligible Class 3 segment consistent with the requirements of § 192.634(b)(3) and (4). Valves must be located at their original class design per § 192.179.

(E) Install, if not already present, at least one cathodic protection pipe-to-soil test station on the eligible Class 3 segment in accordance with § 192.469, with a maximum spacing of

1/2 mile between test stations. Where prevented by obstructions or restricted areas, the test station may be placed in the closest practical location.

(F) Perform a depth of cover survey of the eligible Class 3 segment and take appropriate action to remediate any locations that do not conform to the requirements in § 192.327 for the original class design.

(G) Perform a coating survey of the eligible Class 3 segment and remediate in accordance with the requirements in § 192.461(f) through (h) if any of the following in paragraphs (a)(4)(i)(1) through (5) are present:

(1) Ineffective external coating, as defined in § 192.457;

(2) Adequacy of cathodic protection is measured using a minimum negative (cathodic) polarization voltage shift of 100 millivolts in accordance with paragraph I.A.(3) of appendix D to this part;

(3) Linear anodes are required to maintain cathodic protection in accordance with § 192.463;

(4) Tape wraps or shrink sleeves; or

(5) A history of shielding pipe from cathodic protection.

(H) Notify PHMSA in accordance with § 192.18(a) and (b) that the maximum allowable operating pressure of the eligible Class 3 segment is being confirmed under paragraph (a)(4) of this section.

(ii) Beginning no later than March 16, 2028, or 24 months after the date of the class location change, whichever is later, the operator must comply with the following recurring programmatic requirements:

(A) Except during abnormal operations, the gas transported in the eligible Class 3 segment must not contain:

(1) More than 3 percent carbon dioxide by volume;

(2) More than seven pounds of water per million cubic feet of gas or any free water; and

(3) More than one grain of hydrogen sulfide (H2S) per 100 cubic feet of gas.

(B) Perform close interval surveys of the eligible Class 3 segment using a maximum interval of 5 feet or less with the protected current interrupted at least once every 7 calendar years, with intervals not to exceed 90 months. Evaluate the close interval survey results in accordance with § 192.463 and complete any needed remedial actions in accordance with § 192.465 within 1 year of the survey.

(C) Perform right-of-way patrols of the eligible Class 3 segment in accordance with § 192.705(a) and (c) at least once per month, with intervals not exceeding 45 days.

(D) Perform leakage surveys of the eligible Class 3 segment in accordance with § 192.706 at least four times each calendar year, with intervals not exceeding 4

1/2 months.

(E) Install, if not already present, line markers on the eligible Class 3 segment in accordance with § 192.707. Each line marker must be visible from at least one other line marker. Replace any missing line markers within 30 days of discovery.

(F) Clear shorted casings in the eligible Class 3 segment within 1 year of identifying any metallic or electrolytic short. If clearing the short is impractical, take other measures to minimize corrosion inside the casing.

(G) Conduct a class location study of the eligible Class 3 inspection area in accordance with § 192.609 at least once each calendar year, with intervals not to exceed 15 months.

(H) Whenever the eligible Class 3 segment is exposed and the coating is removed, examine the pipe and weld surfaces for cracking using non-destructive examination methods and procedures that are appropriate for the pipe and integrity threat conditions. Analyze predicted failure pressure and critical strain level of any cracking in accordance with § 192.712 and remediate in accordance with the requirements in paragraph (a)(4) of this section.

(I) The eligible Class 3 inspection area must be reassessed and remediated in accordance with the requirements of paragraph (a)(4) of this section and subpart O of this part.

(iii) Whenever required to comply with the requirements in paragraphs (a)(4)(i) and (ii) of this section, the operator must:

(A) Validate the results of any in-line inspection of an eligible Class 3 inspection area in accordance with API Std 1163 (incorporated by reference, see § 192.7) to at least level 2 validation with sufficient in-situ anomaly validation measurements to achieve an 80 percent confidence level or 100 percent of anomalies, whichever results in fewer validation measurements.

(B) Not use direct assessment as an integrity assessment method for an eligible Class 3 inspection area.

(C) Use a factor 1.39 times the maximum allowable operating pressure when determining the predicted failure pressure on any Class 1 design pipe in an eligible Class 3 segment for one-year conditions in accordance with § 192.933(d)(2)(iv) through (vii) and monitored conditions in accordance with § 192.933(d)(3)(v) through (vi).

(iv) Within 24 months of experiencing an in-service leak from the pipe (including pipe to pipe connections) or rupture, the operator must confirm or revise the maximum allowable operating pressure of an eligible Class 3 segment in accordance with the requirements in paragraph (a)(1), (2), or (3) of this section.

(v) The operator must keep for the life of the pipeline a record of any action taken to comply with the requirements in paragraph (a)(4) of this section.

(vi) The maximum allowable operating pressure of an eligible Class 3 segment confirmed under this paragraph may not produce a corresponding hoop stress that exceeds 72 percent of SMYS for pipe with a Class 1 design factor or 60 percent of SMYS for pipe with a Class 2 design factor.

(vii) Confirmation of maximum allowable operating pressure pursuant to § 192.611(a)(4) is not authorized for gathering lines or distribution lines.

(b) The maximum allowable operating pressure confirmed or revised in accordance with this section, may not exceed the maximum allowable operating pressure established before the confirmation or revision.

(c) Confirmation or revision of the maximum allowable operating pressure of a segment of pipeline in accordance with this section does not preclude the application of §§ 192.553 and 192.555.

(d) Confirmation or revision of maximum allowable operating pressure required as a result of a study under § 192.609 must be completed within 24 months of the change in class location. Pressure reduction under paragraph (a)(1) or (2) of this section within the 24-month period does not preclude establishing the maximum allowable operating pressure of a segment under paragraph (a)(3) of this section or restoring the maximum allowable operating pressure of a segment under paragraph (a)(4) of this section at a later date. Before restoring the maximum allowable operating pressure of an eligible Class 3 segment pursuant to paragraph (a)(4) of this section, an operator must:

(1) Comply with the requirements of § 192.555(b)(1) and (2), (e);

(2) Comply with the requirements in subpart O of this part for MAOP increases; and

(3) Complete all requirements of paragraph (a)(4)(i) of this section.