From: Mike Israni

TO:  Docket Management Facility

U.S. Department of Transportation

1200 New Jersey, SE, West Bldg

Washington D.C. 20590

RE: Docket NO. RSPA-04-19854

Subject: PHMSA and AGA Meeting on Distribution IMP -August 13, 2007

Stacey Gerard (Chief Safety Officer –PHMSA) and Jeff Wiese (Associate
Administrator –PHMSA Pipeline Safety) met with American Gas
Association executives on August 13, 2007 to discuss issues related to
Plastic Pipe Data Committee (PPDC) and fixed inspection intervals under
the current code. 

The Plastic Pipe Data Committee (PPDC), a voluntary group consisting of
representatives of industry, State pipeline safety regulators and PHMSA
and administered by the American Gas Association (AGA), monitors
in-service performance of plastic pipe.  Participating operators send
information on problems occurring with plastic pipe and related fittings
in their pipeline systems.  PPDC periodically analyzes this information
to identify adverse performance trends and problems potentially
requiring action by plastic pipe users.  PPDC information has limited
distribution and is generally not available to operators who do not
participate in the program.  Gas distribution pipeline operators whose
systems include significant amounts of plastic pipe would be better able
to carry out an IM program with knowledge of plastic pipe performance
issues.  

  

PHMSA believes changes to the PPDC process could significantly improve
operator insight into the risks associated with plastic distribution
pipelines.  On PPDC, discussion involved how to strengthen the PPDC
process and to broaden accessibility of results.  AGA indicated that
PPDC members are not willing to make their information publicly
available. 

Fixed inspection intervals under the current code: As part of our
continuing effort to make the pipeline safety regulations more
risk-based, PHMSA is seeking comments in the forthcoming NPRM on an
approach that would allow the States to have more of a role in setting
compliance intervals for distribution operators within a State.  Rather
than continue to require distribution operators to comply with intervals
set by Federal regulation, this approach would let the States examine
each distribution operator’s distribution integrity plan, and based on
the risk assessment included within that plan, work with each operator
to determine the most appropriate risk-based intervals. 

AGA suggested that State regulators should have flexibility to determine
appropriate inspection intervals.  Specifically, AGA provided the
following comments:

Many sections in 49 CFR 192 require prescriptive inspections. The
regulations set a reasonable time interval for specific inspections and
apply the same interval to the entire nation. 

For example, the 49 CFR 192.481 was based upon ASME B31.8 which states:

862.25 Atmospheric Corrosion. Facilities exposed to the atmosphere shall
be periodically inspected for indication of surface corrosion. Where
corrosion is taking place to the extent that public or employee safety
may be affected, the facility shall be reconditioned in accordance with
para. 862.12 or replaced. Special consideration shall be given to
surfaces near the ground line.

192.481 Atmospheric corrosion control:  Monitoring. States (a) Each
operator must inspect each pipeline or portion of pipeline that is
exposed to the atmosphere for evidence of atmospheric corrosion, as
follows:  

Onshore - At least once every 3 calendar years, but with intervals not
exceeding 39 months.

The rate of atmospheric corrosion can vary significantly based upon the
geographic location, corrosive environment, protective coatings, or
other factors. Reference documents, NACE Corrosion Engineers Handbook
(1991 edition) and Metals Handbook (9th ed., Volume 1, pg. 720, ASM
1978) state the typical corrosion rate for unprotected steel
distribution pipe is 24 years. This is the time it takes to lose 70
percent wall thickness. The three-year federal inspection interval must
be applied in the absence of corrosion rate data and other regulatory
alternatives.

There are other prescriptive inspection requirements in 49 CFR 192, such
as, requiring the same leakage survey frequency regardless of material
or local condition under 192.723  Distribution systems:  Leakage
surveys.

