MIL-HDBK-1004/10
APPENDIX E (continued)
(c) Except for cast iron or ductile iron pipe, each segment of
buried or submerged pipe that is required to be repaired because of external
corrosion must be cathodically protected in accordance with this subpart.
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N 192.485
Remedial measures: Transmission lines.
(a) General corrosion. Each segment of transmission line with
general corrosion and with a remaining wall thickness less than that required
for the maximum allowable operating pressure of the pipeline must be replaced
or the operating pressure reduced commensurate with the strength of the pipe
based on actual remaining wall thickness. However, if the area of general
corrosion is small, the corroded pipe may be repaired. Corrosion pitting so
closely grouped as to affect the overall strength of the pipe is considered
general corrosion for the purpose of this paragraph.
(b) Localized corrosion pitting. Each segment of transmission line
pipe with localized corrosion pitting to a degree where leakage might result
must be replaced or repaired, or the operating pressure must be reduced
commensurate with the strength of the pipe, based on the actual remaining wall
thickness in the pits.
[Amdt. 192-4, 36 FR 12302, June 30, 1971, as amended by Amdt. 192-33, 43 FR
39390, Sept. 5, 1978]
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N 192.487 Remedial measures: Distribution lines other than cast iron or
ductile iron lines.
(a) General corrosion. Except for cast iron or ductile iron pipe,
each segment of generally corroded distribution line pipe with a remaining
wall thickness less than that required for the maximum allowable operating
pressure of the pipeline, or a remaining wall thickness less than 30 percent
of the nominal wall thickness, must be replaced. However, if the area of
general corrosion is small, the corroded pipe may be repaired. Corrosion
pitting so closely grouped as to affect the overall strength of the pipe is
considered general corrosion for the purpose of this paragraph.
(b) Localized corrosion pitting. Except for cast iron or ductile
iron pipe, each segment of distribution line pipe with localized corrosion
pitting to a degree where leakage might result must be replaced or repaired.
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N 192.489
Remedial measures:
Cast iron and ductile iron pipelines.
(a) General graphitization. Each segment of cast iron or ductile
iron pipe on which general graphitization is found to a degree where a
fracture or any leakage might result, must be replaced.
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