PHMSA recently published correspondence from Jeff Weiss (Associate Administrator for Pipeline Safety) to AGA concerning the use of External Corrosion Direct Assessment (ECDA) on cased pipelines. PHMSA agrees that neither current regulations nor the NACE RP0502-2002, ‘External Corrosion Direct Assessment Methodology,’ explicitly requires the use of Guided Wave Ultrasonics (GWUT) for cased piping. And, offered clarifications to 49 CFR 192 Subpart O with respect to integrity assessments on cased pipelines:

• Operators are required to assess all pipe segments that can affect high consequence areas (HCAs), including cased piping [49 CFR 192.919(c) and 921(a)]. This rule requires operators to perform a risk assessment of the covered segments to prioritize segments for assessment, but does not allow a risk assessment to be used to not conduct an integrity assessment of all line pipe in a covered segment.
• Though casings make up a very small percentage of the total gas transmission system, some cased piping segments cannot be assessed using in-line inspection (ILI) or pressure testing. The NACE ECDA standard referenced in the Gas IMP regulation does not explicitly reference or identify any technology to assess carrier pipe inside a non-shorted casing. Other technology can be used if the operator demonstrates it can provide an equivalent understanding of the condition of the line pipe [49 CFR 192.921(a)(4)].

PHMSA held a workshop in July to assist pipeline operators, trade associations, and others in addressing concerns with successfully using External Corrosion Direct Assessment integrity evaluation methods and use of other technologies to assess casings in HCAs. See RCP’s related story in the July edition of the DOT Compliance News.