Pipeline Safety: Issues Related to Mechanical Couplings Used in Natural Gas Distribution Systems, 11695-11697 [E8-4155]
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11695
Federal Register / Vol. 73, No. 43 / Tuesday, March 4, 2008 / Notices
(Catalog of Federal Domestic Assistance
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[FR Doc. E8–4090 Filed 3–3–08; 8:45 am]
BILLING CODE 4910–RY–P
DEPARTMENT OF TRANSPORTATION
Pipeline and Hazardous Materials
Safety Administration
Office of Hazardous Materials Safety;
Notice of Delays in Processing of
Special Permits Applications
Pipeline and Hazardous
Materials Safety Administration
(PHMSA), DOT.
AGENCY:
List of applications delayed
more than 180 days.
ACTION:
SUMMARY: In accordance with the
requirements of 49 U.S.C. 5117( c),
PHMSA is publishing the following list
of special permit applications that have
been in process for 180 days or more.
The reason(s) for delay and the expected
completion date for action on each
application is provided in association
with each identified application.
FOR FURTHER INFORMATION CONTACT:
Delmer F. Billings, Director, Office of
Hazardous Materials Special Permits
and Approvals, Pipeline and Hazardous
Materials Safety Administration, U.S.
Department of Transportation, East
Building, PHH–30, 1200 New Jersey
Avenue, Southeast, Washington, DC
20590–0001, (202) 366–4535.
3. Application is technically complex
and is of significant impact or
precedent-setting and requires extensive
analysis.
4. Staff review delayed by other
priority issues or volume of special
permit applications.
Meaning of Application Number
Suffixes
N—New application.
M—Modification request.
PM—Party to application with
modification request.
Issued in Washington, DC, on February 27,
2008.
Delmer F. Billings,
Director, Office of Hazardous Materials,
Special Permits and Approvals.
Key to ‘‘Reason for Delay’’
1. Awaiting additional information
from applicant.
2. Extensive public comment under
review.
Application No.
Reason for
delay of
completion
Applicant
Estimated date
Modification to Special Permits
11579–M ...........
10964–M ...........
13173–M ...........
Austin Powder Company, Cleveland, OR ................................................................................
Kidde Aerospace & Defense, Wilson, NC ................................................................................
Dynetek Industries Ltd., Calgary Alberta, Canada ...................................................................
3, 4
4
1
03–31–2008
03–31–2008
03–31–2008
4
3
1
3
3,4
3,4
03–31–2008
03–31–2008
03–31–2008
03–31–2008
03–31–2008
03–31–2008
New Special Permit Applications
14385–N
14566–N
14576–N
14572–N
14549–N
14402–N
...........
...........
...........
...........
...........
...........
Kansas City Southern Railway Company, Kansas City, MO ...................................................
Nantong CIMCTank Equipment Co. Ltd., Nantong City ..........................................................
Structural Composites Industries(SCI), Pomona, CA ..............................................................
WEW Westerwaelder Eisenwerk, Weitefeld Germany .............................................................
Greif, Inc., Delaware, OR .........................................................................................................
Lincoln Composites, Lincoln, NE ..............................................................................................
[FR Doc. E8–4111 Filed 3–3–08; 8:45 am]
BILLING CODE 4910–60–P
DEPARTMENT OF TRANSPORTATION
Pipeline and Hazardous Materials
Safety Administration
[Docket No. PHMSA–RSPA–2004–19856]
Pipeline Safety: Issues Related to
Mechanical Couplings Used in Natural
Gas Distribution Systems
Pipeline and Hazardous
Materials Safety Administration
(PHMSA), DOT.
ACTION: Notice; issuance of advisory
bulletin.
sroberts on PROD1PC70 with NOTICES
AGENCY:
Recent events concerning
failures of mechanical couplings and
SUMMARY:
VerDate Aug<31>2005
17:57 Mar 03, 2008
Jkt 214001
related appurtenances have raised
concerns about safety in natural gas
distribution systems. This notice
updates information provided in
Advisory Bulletin ADB–86–02 and
advises owners and operators of gas
pipelines to consider the potential
failure modes for mechanical couplings
used for joining and pressure sealing
two pipes together. Failures can occur
when there is inadequate restraint for
the potential stresses on the two pipes,
when the couplings are incorrectly
installed or supported, or when the
coupling components such as
elastomers degrade over time. In
addition, inadequate leak surveys which
fail to identify leaks requiring
immediate repair can lead to more
serious incidents. This notice urges
operators to review their procedures for
using mechanical couplings and ensure
PO 00000
Frm 00085
Fmt 4703
Sfmt 4703
coupling design, installation
procedures, leak survey procedures, and
personnel qualifications meet Federal
requirements. Operators should work
with Federal and State pipeline safety
representatives, manufacturers, and
industry partners to determine how best
to resolve potential issues in their
respective state or region. Documented
repair or replacement programs may
prove beneficial to all stakeholders
involved.
FOR FURTHER INFORMATION CONTACT:
Richard Sanders at (405) 954–7214, or
by e-mail at richard.sanders@dot.gov; or
Max Kieba at (202) 493–0595, or by email at max.kieba@dot.gov.
SUPPLEMENTARY INFORMATION:
E:\FR\FM\04MRN1.SGM
04MRN1
sroberts on PROD1PC70 with NOTICES
11696
Federal Register / Vol. 73, No. 43 / Tuesday, March 4, 2008 / Notices
I. Background
Mechanical couplings are fittings
used for joining and pressure sealing
two pipes together. Other methods of
joining pipe include welding for steel
and heat fusion for plastic. There have
been improvements in materials and
manufacturing methods over the years,
but the basic design concept has not
changed. Most couplings rely on
elastomers and compression as sealing
mechanisms. Couplings appear in a
variety of configurations: Straight or
inline couplings, elbows (45 or 90
degree), tees, reducing couplings (for
joining pipes of different diameters),
and couplings integrated with risers. A
variety of gaskets and sleeves also exist.
Properly installed and supported,
couplings successfully connect steel,
cast iron, copper, and plastic pipes.
However, there is also a history of
significant incidents related to coupling
failures.
Advisory Bulletin ADB–86–02, issued
February 26, 1986, informed natural gas
pipeline operators to review procedures
for using mechanical couplings and
ensure coupling design, procedures, and
personnel qualifications meet 49 CFR
part 192 requirements. ADB–86–02 is
posted on PHMSA’s Web site and in
Docket ID PHMSA–RSPA–2004–19856.
The bulletin discussed pipeline failures
that had been attributed to temperaturerelated contraction of the plastic pipe
and the inadequate restraint capabilities
of mechanical couplings.
Additionally, the National
Transportation Safety Board (NTSB)
issued a Pipeline Accident Report titled
‘‘National Fuel Gas Company, Natural
Gas Explosion and Fire, Sharpsville,
Pennsylvania, February 22, 1985’’
(NTSB/PAR–85/02). The factors
involved in the Sharpsville incident
were similar to those of several other
incidents reported to PHMSA’s Office of
Pipeline Safety. As documented in the
NTSB report, the cyclic effects of
temperature-related contraction and
expansion on plastic pipe in an
improperly designed mechanical joint
can be cumulative and lead to a failure
even after several years of satisfactory
service.
A number of incidents have occurred
since issuance of ADB–86–02. PHMSA
searched 3,417 gas distribution incident
reports submitted to the agency since
1984, and identified 274 incidents that
could potentially include coupling or
fitting failures. After closer examination
of the incident detail, PHMSA
determined 148 of those incidents more
reliably appear to be coupling or fitting
failures on steel or plastic pipe.
Although this accounts for only four to
VerDate Aug<31>2005
17:57 Mar 03, 2008
Jkt 214001
eight percent of all distribution
incidents reported to PHMSA, the
significant incidents within that data, as
well as the potential for additional
significant incidents, should not be
ignored. Significant incidents include
the following: a failure in Buffalo,
Minnesota on February 19, 2004 that
resulted in significant property damage;
a failure in Ramsey, Minnesota on
December 28, 2004 that resulted in three
fatalities and one serious injury; and, a
failure in Wylie, Texas on October 16,
2006 that resulted in two fatalities.
It is important to note that this data
only includes incidents that were
reportable to PHMSA. These numbers
could be much greater if they included
incidents that were reported at the State
level.
In addition to these incidents, a
number of other issues have been cited:
• In 1993, the New York State Public
Service Commission (NY PSC)
concluded an investigation concerning
the increased incidence of leaks
attributed to gaskets and gas quality in
a coupled steel natural gas distribution
system on Long Island.
• In 2005, Washington Gas Company
issued a report on the increased
incidence of natural gas leaks attributed
to gaskets and gas quality on
mechanically coupled steel pipe in a
major portion of its distribution system.
• In 2005, the Public Utilities
Commission of Ohio (PUCO) opened a
statewide investigation due to a series of
natural gas incidents reported to PUCO
by local distribution companies
involving risers, the vertical portions of
the service lines that connect the
distribution systems to customers’
meters. In addition to four reportable
incidents, a number of ‘‘non-incident’’
riser failures were also reported to the
staff. The PUCO opened a case to
examine riser types, reviewing
installation and overall performance
because of the potential risk posed by
risers as links between the gas
distribution service lines and meters,
located near or within a customer’s
premises.
• In addition to the 2004 incidents in
Minnesota already discussed, two other
incidents occurred in the State. After
the first incident, Minnesota’s Office of
Pipeline Safety began to review the
couplings installed in the system in
question. The second incident occurred
while the study was being conducted.
Between 1980 and 2007, seven
incidents occurred in Texas. These are
outlined in a February 2008 Railroad
Commission of Texas report titled
‘‘Study Report on Compression Type
Couplings.’’ (https://www.rrc.state.tx.us/
divisions/gs/pls/TXcouplingrpt.pdf)
PO 00000
Frm 00086
Fmt 4703
Sfmt 4703
These incidents involve a variety of
types and sections of couplings or risers.
For example, the issues surrounding the
Ohio couplings were slightly different
than the Texas couplings. Both were
related to risers, but the Ohio issues
involved the compression mechanisms
located aboveground on the risers that
connect meter settings to underground
service lines. The couplings in Texas
have been located on the ends of service
risers where service lines connect to
risers. While some incidents in question
were reportable to PHMSA and
investigated by PHMSA, those that were
not were investigated by the relevant
State pipeline safety agency. This notice
does not focus on a particular State,
operator, or type of coupling. Rather, it
intends to provide generally applicable
advice on incidents affecting multiple
stakeholders and systems throughout
the country.
Although a number of variables exist,
the safety problem appears to involve
two predominant failure modes. First, in
the cases involving pullout of pipe,
often plastic, from compression
couplings, an additional and perhaps
unique factor produced the pullout
forces. These additional factors could
include cyclic fatigue from changing of
the seasons (especially in northern
climates), or soil shifting by other means
(ground movement from earthquakes or
after heavy rains). Improper installation
(most couplings currently come with
product warnings) or old age (parts of
the coupling deteriorating) could also
have contributed to the pullout. Some
studies found couplings that were
installed with components that differed
from the original manufacturer
specifications, modified prior to
installation, or missing parts entirely.
As another example of incorrect
application, the coupling involved in
the Ramsey, Minnesota incident was
designed to be used on steel pipe, not
plastic, and had a service tee welded to
it contrary to manufacturer’s
recommendations. The common factor
in all incidents involving pullout is that
the compression fitting did not have
adequate restraint to assure safety under
service conditions. In some cases, the
coupling failed after many years of
successful service.
The second failure mode involves
leakage through the sealing surface
between the coupling and the pipe. This
occurred when the integrity of long-term
viscous and elastic effects of the seals
degraded which eventually caused a
leak path to develop. In some cases, a
change in the gas quality in the
distribution system may have
contributed to the failure.
E:\FR\FM\04MRN1.SGM
04MRN1
Federal Register / Vol. 73, No. 43 / Tuesday, March 4, 2008 / Notices
sroberts on PROD1PC70 with NOTICES
Other contributing factors can also
lead to incidents. These factors include
leak surveys conducted in conditions
that prevent gas from properly migrating
to the surface, such as after heavy rains
or certain soil and surface features.
Some incidents indicated leak surveys
involving equipment not calibrated
properly or not appropriate for the
intended use, or personnel not
sufficiently trained. If an operator is
doing proper leak surveys at regular
intervals, an operator can usually detect
a leak early, fix the source of the leak,
and prevent an incident. There have,
however, been cases where a leak
survey, using properly calibrated
equipment showing no problems, was
followed by an incident involving
sudden pullout only weeks later.
Follow-up has already occurred with
some of the incidents mentioned in this
bulletin:
• The NY PSC and the operator
agreed to a replacement program
involving approximately 45,000 natural
gas service lines equipped with
couplings.
• In Ohio, nearly 500,000 risers were
identified by the PUCO’s study as prone
to failure. Currently, the PUCO is
working with the operators who have
these risers and the Ohio Consumers’
Counsel to set up replacement
schedules and address costs.
• In May 2005, Minnesota’s Office of
Pipeline Safety issued a compliance
order to an operator to replace service
lines installed prior to January 1, 1984,
or visually inspect the entire service
line to verify it contains only
mechanical fittings that comply with 49
CFR 192.283(b). Any mechanical fittings
identified that did not meet the
requirements were required to be
replaced.
• The Railroad Commission of Texas
has required operators to replace, within
a 2-year period, 97,000 remaining old
mechanical couplings that have been in
service for some 28 to 30 years. In
addition, the Railroad Commission of
Texas has adopted mandatory
replacement programs in an effort to
remove compression couplings found
leaking on both steel and plastic pipe
that are susceptible to pullout.
A number of other studies, tests, and
repair or replacement programs, some of
them voluntary, have been conducted in
other States.
II. Advisory Bulletin (ADB–08–02)
To: All Gas Distribution Operators.
Subject: Identifying Issues with
Mechanical Coupling That Could Lead
to Failure.
Advisory: Due to variables related to
age of couplings, specific procedures
VerDate Aug<31>2005
17:57 Mar 03, 2008
Jkt 214001
and installation practices, and
conditions specific to certain regions of
the country, it is difficult to cite
common criteria affecting all failures
that operators should address. However,
PHMSA advises operators of gas
distribution pipelines using mechanical
couplings to do the following to ensure
compliance with 49 CFR part 192:
(1) Review procedures for using
mechanical couplings, including the
coupling design and installation and
ensure that they meet manufacturer’s
recommendations;
(2) Review leak survey procedures to
ensure that leak surveys are properly
conducted, taking into account other
contributing factors (i.e., weather
conditions, calibration); and,
(3) Review personnel qualifications to
ensure they address leak surveys
sufficiently.
PHMSA also advises operators of gas
distribution pipelines using mechanical
couplings to consider taking the
following measures to reduce the risk of
failures of mechanical couplings:
(4) Use Category 1 fittings only if
mechanical couplings are used on pipe
sizes 1⁄2′ CTS (Copper Tube Size) to 2′
IPS (Iron Pipe Size). Per ASTM D2513–
99 titled ‘‘Standard Specification for
Thermoplastic Gas Pressure Pipe,
Tubing and Fittings,’’ Category 1 is a
mechanical joint design that provides a
seal plus a resistance to a force on the
pipe end equal to or greater than that
which will cause a permanent
deformation of the pipe. At this time
there is insufficient data to indicate
there are issues involving fittings for
larger diameter pipe. PHMSA will
revisit if such issues do arise with larger
diameter pipe.
(5) Improve recordkeeping on specific
couplings that exist, i.e., their type,
installation date, maintenance schedule,
and any failures encountered, to help
identify a trend of problems that may
occur with a specific coupling or type
of installation.
(6) Consider whether to adopt a full
replacement program if there are too
many unknowns related to couplings in
service.
(7) Work with Federal and State
pipeline safety representatives,
manufacturers, and industry partners to
determine how best to resolve potential
issues in their respective state or region.
Documented repair and replacement
programs may prove beneficial to all
stakeholders involved. If operators are
unsure of the appropriate
representative, contact the individual(s)
listed in this advisory bulletin for
further information.
PO 00000
Frm 00087
Fmt 4703
Sfmt 4703
11697
Issued in Washington, DC, on February 28,
2008.
Jeffrey D. Wiese,
Associate Administrator for Pipeline Safety.
[FR Doc. E8–4155 Filed 3–3–08; 8:45 am]
BILLING CODE 4910–60–P
DEPARTMENT OF THE TREASURY
Office of Foreign Assets Control
Additional Designations of Entities
Pursuant to Executive Order 13448
Office of Foreign Assets
Control, Treasury.
ACTION: Notice.
AGENCY:
SUMMARY: The Treasury Department’s
Office of Foreign Assets Control
(‘‘OFAC’’) is publishing the names of
two newly-designated entities whose
property and interests in property are
blocked pursuant to Executive Order
13448 of October 18, 2007, ‘‘Blocking
Property and Prohibiting Certain
Transactions Related to Burma.’’
DATES: The designation by the Director
of OFAC of two entities identified in
this notice, pursuant to Executive
Orders 13448, is effective February 25,
2008.
FOR FURTHER INFORMATION CONTACT:
Assistant Director, Compliance
Outreach & Implementation, Office of
Foreign Assets Control, Department of
the Treasury, 1500 Pennsylvania
Avenue NW., (Treasury Annex),
Washington, DC 20220, Tel.: 202/622–
2490.
SUPPLEMENTARY INFORMATION:
Electronic and Facsimile Availability
Information about these designations
and additional information concerning
OFAC are available from OFAC’s Web
site (https://www.treas.gov.ofac) or via
facsimile through a 24-hour fax-ondemand service, Tel.: 202/622–0077.
Background
On October 18, 2007, the President
signed Executive Order 13448 (the
‘‘Order’’) pursuant to, inter alia, the
International Emergency Economic
Powers Act (50 U.S.C. 1701 et seq.). In
the Order, the President took additional
steps with respect to, and expanded, the
national emergency declared in
Executive Order 13047 of May 20, 1997,
to address the Government of Burma’s
continued repression of the democratic
opposition. The President identified
twelve individuals and entities as
subject to the economic sanctions in the
Annex to the Order.
Section 1 of the Order blocks, with
certain exceptions, all property and
E:\FR\FM\04MRN1.SGM
04MRN1
]]>Agencies
[Federal Register Volume 73, Number 43 (Tuesday, March 4, 2008)]
[Notices]
[Pages 11695-11697]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-4155]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Pipeline and Hazardous Materials Safety Administration
[Docket No. PHMSA-RSPA-2004-19856]
Pipeline Safety: Issues Related to Mechanical Couplings Used in
Natural Gas Distribution Systems
AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA),
DOT.
ACTION: Notice; issuance of advisory bulletin.
-----------------------------------------------------------------------
SUMMARY: Recent events concerning failures of mechanical couplings and
related appurtenances have raised concerns about safety in natural gas
distribution systems. This notice updates information provided in
Advisory Bulletin ADB-86-02 and advises owners and operators of gas
pipelines to consider the potential failure modes for mechanical
couplings used for joining and pressure sealing two pipes together.
Failures can occur when there is inadequate restraint for the potential
stresses on the two pipes, when the couplings are incorrectly installed
or supported, or when the coupling components such as elastomers
degrade over time. In addition, inadequate leak surveys which fail to
identify leaks requiring immediate repair can lead to more serious
incidents. This notice urges operators to review their procedures for
using mechanical couplings and ensure coupling design, installation
procedures, leak survey procedures, and personnel qualifications meet
Federal requirements. Operators should work with Federal and State
pipeline safety representatives, manufacturers, and industry partners
to determine how best to resolve potential issues in their respective
state or region. Documented repair or replacement programs may prove
beneficial to all stakeholders involved.
FOR FURTHER INFORMATION CONTACT: Richard Sanders at (405) 954-7214, or
by e-mail at richard.sanders@dot.gov; or Max Kieba at (202) 493-0595,
or by e-mail at max.kieba@dot.gov.
SUPPLEMENTARY INFORMATION:
[[Page 11696]]
I. Background
Mechanical couplings are fittings used for joining and pressure
sealing two pipes together. Other methods of joining pipe include
welding for steel and heat fusion for plastic. There have been
improvements in materials and manufacturing methods over the years, but
the basic design concept has not changed. Most couplings rely on
elastomers and compression as sealing mechanisms. Couplings appear in a
variety of configurations: Straight or inline couplings, elbows (45 or
90 degree), tees, reducing couplings (for joining pipes of different
diameters), and couplings integrated with risers. A variety of gaskets
and sleeves also exist. Properly installed and supported, couplings
successfully connect steel, cast iron, copper, and plastic pipes.
However, there is also a history of significant incidents related to
coupling failures.
Advisory Bulletin ADB-86-02, issued February 26, 1986, informed
natural gas pipeline operators to review procedures for using
mechanical couplings and ensure coupling design, procedures, and
personnel qualifications meet 49 CFR part 192 requirements. ADB-86-02
is posted on PHMSA's Web site and in Docket ID PHMSA-RSPA-2004-19856.
The bulletin discussed pipeline failures that had been attributed to
temperature-related contraction of the plastic pipe and the inadequate
restraint capabilities of mechanical couplings.
Additionally, the National Transportation Safety Board (NTSB)
issued a Pipeline Accident Report titled ``National Fuel Gas Company,
Natural Gas Explosion and Fire, Sharpsville, Pennsylvania, February 22,
1985'' (NTSB/PAR-85/02). The factors involved in the Sharpsville
incident were similar to those of several other incidents reported to
PHMSA's Office of Pipeline Safety. As documented in the NTSB report,
the cyclic effects of temperature-related contraction and expansion on
plastic pipe in an improperly designed mechanical joint can be
cumulative and lead to a failure even after several years of
satisfactory service.
A number of incidents have occurred since issuance of ADB-86-02.
PHMSA searched 3,417 gas distribution incident reports submitted to the
agency since 1984, and identified 274 incidents that could potentially
include coupling or fitting failures. After closer examination of the
incident detail, PHMSA determined 148 of those incidents more reliably
appear to be coupling or fitting failures on steel or plastic pipe.
Although this accounts for only four to eight percent of all
distribution incidents reported to PHMSA, the significant incidents
within that data, as well as the potential for additional significant
incidents, should not be ignored. Significant incidents include the
following: a failure in Buffalo, Minnesota on February 19, 2004 that
resulted in significant property damage; a failure in Ramsey, Minnesota
on December 28, 2004 that resulted in three fatalities and one serious
injury; and, a failure in Wylie, Texas on October 16, 2006 that
resulted in two fatalities.
It is important to note that this data only includes incidents that
were reportable to PHMSA. These numbers could be much greater if they
included incidents that were reported at the State level.
In addition to these incidents, a number of other issues have been
cited:
In 1993, the New York State Public Service Commission (NY
PSC) concluded an investigation concerning the increased incidence of
leaks attributed to gaskets and gas quality in a coupled steel natural
gas distribution system on Long Island.
In 2005, Washington Gas Company issued a report on the
increased incidence of natural gas leaks attributed to gaskets and gas
quality on mechanically coupled steel pipe in a major portion of its
distribution system.
In 2005, the Public Utilities Commission of Ohio (PUCO)
opened a statewide investigation due to a series of natural gas
incidents reported to PUCO by local distribution companies involving
risers, the vertical portions of the service lines that connect the
distribution systems to customers' meters. In addition to four
reportable incidents, a number of ``non-incident'' riser failures were
also reported to the staff. The PUCO opened a case to examine riser
types, reviewing installation and overall performance because of the
potential risk posed by risers as links between the gas distribution
service lines and meters, located near or within a customer's premises.
In addition to the 2004 incidents in Minnesota already
discussed, two other incidents occurred in the State. After the first
incident, Minnesota's Office of Pipeline Safety began to review the
couplings installed in the system in question. The second incident
occurred while the study was being conducted.
Between 1980 and 2007, seven incidents occurred in Texas. These are
outlined in a February 2008 Railroad Commission of Texas report titled
``Study Report on Compression Type Couplings.'' (https://
www.rrc.state.tx.us/divisions/gs/pls/TXcouplingrpt.pdf)
These incidents involve a variety of types and sections of
couplings or risers. For example, the issues surrounding the Ohio
couplings were slightly different than the Texas couplings. Both were
related to risers, but the Ohio issues involved the compression
mechanisms located aboveground on the risers that connect meter
settings to underground service lines. The couplings in Texas have been
located on the ends of service risers where service lines connect to
risers. While some incidents in question were reportable to PHMSA and
investigated by PHMSA, those that were not were investigated by the
relevant State pipeline safety agency. This notice does not focus on a
particular State, operator, or type of coupling. Rather, it intends to
provide generally applicable advice on incidents affecting multiple
stakeholders and systems throughout the country.
Although a number of variables exist, the safety problem appears to
involve two predominant failure modes. First, in the cases involving
pullout of pipe, often plastic, from compression couplings, an
additional and perhaps unique factor produced the pullout forces. These
additional factors could include cyclic fatigue from changing of the
seasons (especially in northern climates), or soil shifting by other
means (ground movement from earthquakes or after heavy rains). Improper
installation (most couplings currently come with product warnings) or
old age (parts of the coupling deteriorating) could also have
contributed to the pullout. Some studies found couplings that were
installed with components that differed from the original manufacturer
specifications, modified prior to installation, or missing parts
entirely. As another example of incorrect application, the coupling
involved in the Ramsey, Minnesota incident was designed to be used on
steel pipe, not plastic, and had a service tee welded to it contrary to
manufacturer's recommendations. The common factor in all incidents
involving pullout is that the compression fitting did not have adequate
restraint to assure safety under service conditions. In some cases, the
coupling failed after many years of successful service.
The second failure mode involves leakage through the sealing
surface between the coupling and the pipe. This occurred when the
integrity of long-term viscous and elastic effects of the seals
degraded which eventually caused a leak path to develop. In some cases,
a change in the gas quality in the distribution system may have
contributed to the failure.
[[Page 11697]]
Other contributing factors can also lead to incidents. These
factors include leak surveys conducted in conditions that prevent gas
from properly migrating to the surface, such as after heavy rains or
certain soil and surface features. Some incidents indicated leak
surveys involving equipment not calibrated properly or not appropriate
for the intended use, or personnel not sufficiently trained. If an
operator is doing proper leak surveys at regular intervals, an operator
can usually detect a leak early, fix the source of the leak, and
prevent an incident. There have, however, been cases where a leak
survey, using properly calibrated equipment showing no problems, was
followed by an incident involving sudden pullout only weeks later.
Follow-up has already occurred with some of the incidents mentioned
in this bulletin:
The NY PSC and the operator agreed to a replacement
program involving approximately 45,000 natural gas service lines
equipped with couplings.
In Ohio, nearly 500,000 risers were identified by the
PUCO's study as prone to failure. Currently, the PUCO is working with
the operators who have these risers and the Ohio Consumers' Counsel to
set up replacement schedules and address costs.
In May 2005, Minnesota's Office of Pipeline Safety issued
a compliance order to an operator to replace service lines installed
prior to January 1, 1984, or visually inspect the entire service line
to verify it contains only mechanical fittings that comply with 49 CFR
192.283(b). Any mechanical fittings identified that did not meet the
requirements were required to be replaced.
The Railroad Commission of Texas has required operators to
replace, within a 2-year period, 97,000 remaining old mechanical
couplings that have been in service for some 28 to 30 years. In
addition, the Railroad Commission of Texas has adopted mandatory
replacement programs in an effort to remove compression couplings found
leaking on both steel and plastic pipe that are susceptible to pullout.
A number of other studies, tests, and repair or replacement
programs, some of them voluntary, have been conducted in other States.
II. Advisory Bulletin (ADB-08-02)
To: All Gas Distribution Operators.
Subject: Identifying Issues with Mechanical Coupling That Could
Lead to Failure.
Advisory: Due to variables related to age of couplings, specific
procedures and installation practices, and conditions specific to
certain regions of the country, it is difficult to cite common criteria
affecting all failures that operators should address. However, PHMSA
advises operators of gas distribution pipelines using mechanical
couplings to do the following to ensure compliance with 49 CFR part
192:
(1) Review procedures for using mechanical couplings, including the
coupling design and installation and ensure that they meet
manufacturer's recommendations;
(2) Review leak survey procedures to ensure that leak surveys are
properly conducted, taking into account other contributing factors
(i.e., weather conditions, calibration); and,
(3) Review personnel qualifications to ensure they address leak
surveys sufficiently.
PHMSA also advises operators of gas distribution pipelines using
mechanical couplings to consider taking the following measures to
reduce the risk of failures of mechanical couplings:
(4) Use Category 1 fittings only if mechanical couplings are used
on pipe sizes \1/2\' CTS (Copper Tube Size) to 2' IPS (Iron Pipe Size).
Per ASTM D2513-99 titled ``Standard Specification for Thermoplastic Gas
Pressure Pipe, Tubing and Fittings,'' Category 1 is a mechanical joint
design that provides a seal plus a resistance to a force on the pipe
end equal to or greater than that which will cause a permanent
deformation of the pipe. At this time there is insufficient data to
indicate there are issues involving fittings for larger diameter pipe.
PHMSA will revisit if such issues do arise with larger diameter pipe.
(5) Improve recordkeeping on specific couplings that exist, i.e.,
their type, installation date, maintenance schedule, and any failures
encountered, to help identify a trend of problems that may occur with a
specific coupling or type of installation.
(6) Consider whether to adopt a full replacement program if there
are too many unknowns related to couplings in service.
(7) Work with Federal and State pipeline safety representatives,
manufacturers, and industry partners to determine how best to resolve
potential issues in their respective state or region.
Documented repair and replacement programs may prove beneficial to
all stakeholders involved. If operators are unsure of the appropriate
representative, contact the individual(s) listed in this advisory
bulletin for further information.
Issued in Washington, DC, on February 28, 2008.
Jeffrey D. Wiese,
Associate Administrator for Pipeline Safety.
[FR Doc. E8-4155 Filed 3-3-08; 8:45 am]
BILLING CODE 4910-60-P
