# Public Advocates Office, California PUC — Pipeline Safety Interpretation

- **operation:** document
- **citation:** PI-20-0009
- **title:** Public Advocates Office, California PUC — Pipeline Safety Interpretation
- **source type:** guidance
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** guidance
- **official:** true
- **published on:** 2020-04-24
- **effective on:** Not available
- **summary:** PI-20-0009 response to Public Advocates Office, California PUC concerning 192.113.
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- **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-pi-20-0009
- **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/pipeline/interpretations/73931/california-public-advocates-office-pi-20-0009-05-07-2020-part-192-113-letter-signed.pdf
**body:**

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U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
May 7, 2020
Mr. Darwin E. Farrar
Chief Counsel
Public Advocates Office
California Public Utilities Commission
505 Van Ness Avenue
San Francisco, CA 94102
Dear Mr. Farrar:
In a letter to the Pipeline and Hazardous Materials Safety Administration (PHMSA), dated
March 10, 2020, you requested an interpretation of 49 Code of Federal Regulations (CFR) Part
192. Specifically, you requested an interpretation of § 192.113 as it relates to the longitudinal
joint factor (E) for steel used under § 192.105 to determine a natural gas pipeline design
maximum allowable operating pressure (MAOP).
You ask for clarification whether a value of E = 1.0 or E = 0.8 is used to calculate MAOP for
steel pipelines with diameter of over four inches, installed after 1970, with an unknown
longitudinal joint, and is used in the construction or replacement sections of natural gas
pipelines.
You stated that the California Public Utilities Commission recently required its Safety and
Enforcement Division to oversee an audit of the MAOP-related records of the Southern
California Gas Company and San Diego Gas and Electric Company natural gas transmission
Line 1600. You stated, in the Line 1600 case, the longitudinal joint type in certain segments is
unknown. However, you stated an auditor who examined the records on the pipeline has stated
that because the operator has represented there are no lap weld or furnace butt welds pipe in
these segments, an E = 1.0 may be used. You stated this is in contradiction to the requirement
under § 192.113 for a type of longitudinal joint that cannot be determined.
You stated that the Public Advocates Office seeks PHMSA’s interpretation of the following
questions based on the concerns set forth above. PHMSA’s responses follow the questions.
Question 1: Are all Line 1600 segments installed after 49 CFR Part 192 was codified in
1970, that are over four inches, and that have an unknown longitudinal seam type, required to
have a longitudinal joint factor of no greater than 0.8, assuming it is conclusively determined
that such segments do not contain lap welds or butt welds (which would necessitate a
longitudinal joint factor of no greater than 0.6)?
The Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations (49 CFR
Parts 190-199) in the form of interpretation letters. These letters reflect the agency's current application of the regulations to the specific facts
presented by the person requesting the clarification. Interpretations are not generally applicable, do not create legally-enforceable rights or
obligations, and are provided to help the specific requestor understand how to comply with the regulations.

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2
PHMSA Response: Yes, the table included in § 192.113 states that if the type of
longitudinal joint cannot be determined, the joint factor to be used must not exceed that
designated for ‘‘Other.’’ For “Other” pipe over 4 inches (102 millimeters) the longitudinal
joint factor E is 0.8. Methods for determining the pipe joint factor can be based upon factors,
such as whether the pipe diameters, wall thicknesses, yield strength, and manufacturing
period are applicable for that seam type. Also, the seam type can be determined based upon
inspections of the pipe, such as excavations of the pipe or pipe removals.
Question 2: Given the applicable ASA [American Standard Code for Pressure Piping]
standards establishing MAOP, dating back to 1955 and continuing until the codification of
49 CFR Part 192 in 1970, is it proper to assume a longitudinal joint factor of no greater than
0.8 for pipe segments installed during that period, which have unknown longitudinal seam
types, and which are over four inches in diameter, even if it is conclusively determined that
such pipes do not contain lap welds or butt welds?
PHMSA Response: If the longitudinal seam type of a pipeline is unknown, a value of E
equal to 0.8 must be used in § 192.105 for determining the design pressure of pipelines with
a diameter greater than 4 inches.
If the pipelines’ MAOPs were established prior to 1970, under the § 192.619(c)
requirements, the operators can operate them under those established MAOPs. However, a
segment of pipeline that has been relocated or replaced cannot be returned to service without
meeting the testing requirements under § 192.503, as well as the design and pressure test
requirements in § 192.619(a)(1-2).
Question 3: Where the answer to question 1 or 2 is yes, does the resulting required reduction
of the longitudinal joint factor from 1.0 to 0.8 also require that when the design is based upon
MAOP required under 49 CFR § 192.105 to be reduced by 20%, assuming all other inputs
into that formula are accurate and are otherwise unchanged?
PHMSA Response: Yes, since the MAOP is determined based on the design pressure
requirements in § 192.105, and with E being a proportional factor in the equation in
§ 192.105, then a reduction of E from 1.0 to 0.8 is a 20% reduction in MAOP.
If we can be of further assistance, please contact Tewabe Asebe at 202-366-5523.
Sincerely,
JOHN A
GALE
Digitally signed
by JOHN A GALE
Date: 2020.05.11
08:10:55 -04'00'
John A. Gale
Director, Office of Standards
and Rulemaking
The Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety provides written clarifications of the Regulations (49 CFR
Parts 190-199) in the form of interpretation letters. These letters reflect the agency's current application of the regulations to the specific facts
presented by the person requesting the clarification. Interpretations are not generally applicable, do not create legally-enforceable rights or
obligations, and are provided to help the specific requestor understand how to comply with the regulations.

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Public Advocates Office
California Public Utilities Commission
505 Van Ness Avenue
San Francisco, California 94102
Tel: 415-703-1584
www.publicadvocaLes.cpuc.ca.gov
March 10, 2020
John Gale
Director, Standards and Rulemaking
U.S. Department of Transportation
Pipeline and Hazardous Materials Safety Administration
East Building, Second Floor
1200 New Jersey Avenue SE
Washington, D.C. 20590
Dear Mr. Gale:
The Public Advocates Office is the independent consumer advocate at the
California Public Utilities Commission. We are writing to the Pipeline and Hazardous
Materials Safety Administration (PHMSA) to request an interpretation of the regulations
at 49 Code of Federal Regulations (CFR) § 192.113 that address determinations
regarding the Longitudinal Joint Factor (LJF) for steel pipe, a required factor for
determining the design-based Maximum Allowable Operating Pressure (MAOP) for
natural gas pipelines under 49 CFR §192.105.
Specifically, we seek to clarify that for pipelines installed after 1970, if a transmission
line is over four inches, has steel pipe with a type oflongitudinal joint that cannot be
determined because it is unknown, and is used in the construction or replacement
sections, does 49 CFR §192.113 allow for a Longitudinal Joint Factor value of 1.0, or
must the Longitudinal Joint Factor be no greater than 0.8?
Southern California Gas Company and San Diego Gas & Electric Line 1600
The California Public Utilities Commission (CPUC) recently required its Safety and
Enforcement Division (SED) to oversee an audit of the MAOP-related records of the
Southern California Gas Company (SoCalGas) and San Diego Gas & Electric Company

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Page2
(SDG&E)1 transmission Line 1600 (Line 1600 Audit).2 In this case, the longitudinal
joint type in certain segments of a transmission line is unknown. However, an auditor
who examined the records on that line has stated that because the operator has
represented there are no lap weld or furnace butt welds pipe in these segments, a 1.0 LJP
may be used.J Specifically, the Line 1600 Audit states:
There are records for pipe segments that did not have a seam type
listed in the pipe specifications. SDG&E performed an internal
study on long seam types based on the history of the company's Pipe
Design Standards. No Lap Weld or Furnace Butt Weld pipe was
used in the construction and replacement sections of Line 1600.
Therefore, a longitudinal joint factor of 1. 0 can be used when there
is no specification of seam type on a document.1' ~
The Public Advocates Office is concerned with both the operator's and the auditor's
assertion that the MAOP of design is being properly calculated for Line 1600.
It is the Public Advocates Office's understanding that 49 CPR §192.113 requires that, in
cases where a transmission line is over four inches in diameter, and the type of
longitudinal joint cannot be determined, the longitudinal joint factor to be used in the
formula to calculate the design MAOP must not exceed 0.8.6
The Public Advocates Office is also concerned that MAOP of design asserted by both the
operator and the auditor does not comport with the American Standards Association
(ASA) standards in effect between 1955 and when 49 CPR Part 192 was adopted in 1970.
Indeed, the ASA standards in effect from 1955 and 1967 for "Joint Efficiency" provide
1 Collectively the operator.
1 See D.18-06-028, mimeo, p. 129, Ordering Paragraph 9. Available at:
http://docs.cpuc.ca.gov/PublishedDocs/Publ ished/G000/M.217 /K0 13/2170 13446.pdf
See also, Line 1600 MAOP Audit-Interim Report, p. 3. "RCP was selected as an independent auditor for
this audit pursuant to California Public Utilities Commission (CPUC) D.18-06-028 (Decision). The
CPUC's Safety and Enforcement Division (SEO) is directed to oversee this audit of San Diego Gas &
Electric Company's (SDG&E) and Southern California Gas Company's (SoCalGas) MAOP records for
Line 1600."
;! The auditor made this statement based on the knowledge of SoCalGas and SDG&E. The results of this
audit are provided as Attachment A and the Line 1600 Audit can be found at:
http://docs.cpuc.ca.gov/SearchRes.aspx?docformat=ALL&DocID=323 l 70376
~ See Attachment C, p. 10, point iii. Emphasis added.
~ The Line 1600 Audit was publicly provided by the Safety and Enforcement Division in redacted form.
Public Advocates Office has received the version that SoCalGas/SDG&E asserts has confidential
information. Public Advocates Office is providing the public version as Attachment A.
6 All entries in the Line 1600 Audit show that the outside diameter of the pipeline is over four inches.

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Page3
that, "[i]fthe type oflongitudinaljoint can be determined with certainty, the
corresponding Longitudinal Joint Factor "E" (Table 841.12) may be used. Otherwise, the
factor 'E' shall be taken as 0.60 for the pipe 4 inches and smaller, or 0.80 for pipe over 4
inches."1
The Public Advocates Office understands that the conclusion that, "a longitudinal joint
factor of 1.0 can be used when there is no specification of seam type on a document,"
would render meaningless the 49 CFR § 192.113 requirement that a pipe over 4 inches in
the "Other" category have an LJF no greater than 0.8. Relatedly, the Public Advocates
Office understands this conclusion would also render meaningless the portion of the table
under 49 CFR §192.113 that provides a 0.8 LJF for "Other" pipe classes that are not
shown on that table.
The Public Advocates Office also understands that this same conclusion would not
comport with the ASA standards in effect from 1955 until the adoption of 49 CFR Part
192 in 1970, because those standards prescribed a LJF of0.8 for pipe over four inches
where the type of longitudinal joint was uncertain or unknown.
A review of the record shows pre-1971 and post 1970 audit entries that have imputed
LJF's of 1.0, even though the records indicate the operator does not know the seam type.
All of these entries have unknown pipe manufacturers, and an outside diameter of over
four inches.~
The Public Advocates Office seeks PHMSA's interpretation of the following questions
based on the concerns set forth above:
1. Are all Line 1600 segments installed after 49 CFR Part 192 was
codified in 1970, that are over four inches, and that have an unknown
longitudinal seam type, required to have a longitudinal joint factor of no
greater than 0.8, assuming it is conclusively determined that such
segments do not contain lap welds or butt welds (which would
necessitate a longitudinal joint factor of no greater than 0.6)?
1 See American Standard Code for Pressure Piping (ASA) B31.1.8-1955, "Gas Transmission and
Distribution Piping Systems" §811.27.D, pp. 17-18.
See also USA Standard Code for Pressure Piping (USAS) B31.8-1967 "Gas Transmission and
Distribution Piping Systems", §811.253.D, p. 11.
l! These long seam entries and pipe manufacture entries are redacted in the Line 1600 Audit that was
publicly provided by SED. SoCalGas has marked these entries as confidential in the data response to the
Public Advocates Office. These blacked out entries can be seen beginning on page 19 of 32, with the
document entitled "Audit Line 1600-Final."

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2. Given the applicable ASA standards establishing MAOP, dating back to
1955 and continuing until the codification of 49 CFR Part 192 in 1970,
is it proper to assume a longitudinal joint factor of no greater than 0.8
for pipe segments installed during that period, which have unknown
longitudinal seam types, and which are over four inches in diameter,
even if it is conclusively determined that such pipes do not contain lap
welds or butt welds? ,
3. Where the answer to question 1 or 2 is yes, does the resulting required
reduction of the LJF from).0 to 0.8 also require that the design based
MAOP required under 49 CFR §192.105 be reduced by 20%, assuming
all other inputs into that formula are accurate and are otherwise
unchanged?
If you wish to discuss any questions or concerns, please contact Dr. Nathaniel Skinner,
Public Advocates Office Safety Branch Program Manager, at (415) 703-1393.
Darwin E. Farrar
Chief Counsel
Public Advocates Office-
California Public Utilities Commission
Enclosure
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