Louisiana Administrative Code › Title 43 - NATURAL RESOURCES › Part XIII - Office of Conservation-Pipeline Safety › Subpart 3 - Transportation of Natural Gas or Other Gas by Pipeline: Minimum Safety Standards [49 CFR Part 192] › Chapter 29 - Maintenance [49 CFR Part 192 Subpart M] › Section XIII-2912 - Analysis of Predicted Failure Pressure [49 CFR 192.712]

Current through Register Vol. 50, No. 6, June 20, 2024
A. Applicability. Whenever required by this
				  part, operators of onshore steel transmission pipelines must analyze anomalies
				  or defects to determine the predicted failure pressure at the location of the
				  anomaly or defect, and the remaining life of the pipeline segment at the
				  location of the anomaly or defect, in accordance with this Section.
				  [49 CFR
				  192.712(a)]
B. Corrosion Metal Loss. When analyzing
				  corrosion metal loss under this Section, an operator must use a suitable
				  remaining strength calculation method including, ASME/ANSI B31G (incorporated
				  by reference, see §507); R-STRENG (incorporated by reference, see
				  §507); or an alternative equivalent method of remaining strength
				  calculation that will provide an equally conservative result. [49 CFR
				  192.712(b)]
C. Reserved [49
				  CFR 192.712(c)]
D. Cracks and Crack-Like Defects
				  [49 CFR
				  192.712(d)]
1. Crack Analysis Models. When analyzing
				  cracks and crack-like defects under this Section, an operator must determine
				  predicted failure pressure, failure stress pressure, and crack growth using a
				  technically proven fracture mechanics model appropriate to the failure mode
				  (ductile, brittle or both), material properties (pipe and weld properties), and
				  boundary condition used (pressure test, ILI, or other). [49 CFR
				  192.712(d)(1)]
2. Analysis for Crack Growth and Remaining
				  Life. If the pipeline segment is susceptible to cyclic fatigue or other loading
				  conditions that could lead to fatigue crack growth, fatigue analysis must be
				  performed using an applicable fatigue crack growth law (for example, Paris Law)
				  or other technically appropriate engineering methodology. For other degradation
				  processes that can cause crack growth, appropriate engineering analysis must be
				  used. The above methodologies must be validated by a subject matter expert to
				  determine conservative predictions of flaw growth and remaining life at the
				  maximum allowable operating pressure. The operator must calculate the remaining
				  life of the pipeline by determining the amount of time required for the crack
				  to grow to a size that would fail at maximum allowable operating pressure.
				  [49 CFR
				  192.712(d)(2)]
a. When calculating crack size that would
				  fail at MAOP, and the material toughness is not documented in traceable,
				  verifiable, and complete records, the same Charpy v-notch toughness value
				  established in Paragraph E.2 of this Section must be used. [49 CFR
				  192.712(d)(2)(i)]
b. Initial and final flaw size must be
				  determined using a fracture mechanics model appropriate to the failure mode
				  (ductile, brittle or both) and boundary condition used (pressure test, ILI, or
				  other). [49 CFR
				  192.712(d)(2)(ii)]
c. An operator must re-evaluate the remaining
				  life of the pipeline before 50 percent of the remaining life calculated by this
				  analysis has expired. The operator must determine and document if further
				  pressure tests or use of other assessment methods are required at that time.
				  The operator must continue to re-evaluate the remaining life of the pipeline
				  before 50 percent of the remaining life calculated in the most recent
				  evaluation has expired. [49 CFR
				  192.712(d)(2)(iii)]
3. Cracks that Survive Pressure
				  Testing. For cases in which the operator does not have in-line inspection crack
				  anomaly data and is analyzing potential crack defects that could have survived
				  a pressure test, the operator must calculate the largest potential crack defect
				  sizes using the methods in Paragraph D.1 of this Section. If pipe material
				  toughness is not documented in traceable, verifiable, and complete records, the
				  operator must use one of the following for Charpy v-notch toughness values
				  based upon minimum operational temperature and equivalent to a full-size
				  specimen value: [49 CFR
				  192.712(d)(3)]
a. Charpy v-notch toughness values from
				  comparable pipe with known properties of the same vintage and from the same
				  steel and pipe manufacturer; [49 CFR
				  192.712(d)(3)(i)]
b. a conservative Charpy v-notch toughness
				  value to determine the toughness based upon the material properties
				  verification process specified in §2707; [49
				  CFR
				  192.712(d)(3)(ii)]
c. a full size equivalent Charpy v- notch
				  upper-shelf toughness level of 120 ft.-lbs.; or [49
				  CFR
				  192.712(d)(3)(iii)]
d. other appropriate values that an operator
				  demonstrates can provide conservative Charpy v-notch toughness values of the
				  crack-related conditions of the pipeline segment. Operators using an assumed
				  Charpy v-notch toughness value must notify PHMSA in accordance with
				  §518 [49 CFR
				  192.712(d)(3)(iv)]