The Department of Transportation’s Office of Pipeline Safetyreported yesterday that El Paso Natural Gas has submitted theresults of its tests on the one line (Line 1110) that was the leastaffected by the Aug. 19 explosion and fire on El Paso’s South Mainsystem, as well as a plan for returning the line back to operation.

“At this point we are reviewing” both, said DOT spokeswomanDebbie Hinz. Asked when there would be more definite news aboutwhen Line 1110 would be returned to service, she said “when weapprove it.”

In related action, the OPS has issued a bulletin to owners andoperators of natural gas transmission pipelines to review theirmonitoring programs and operations for determining the “existenceor severity” of internal corrosion in their systems.

The OPS bulletin comes after its preliminary investigation intothe blast on El Paso near Carlsbad, NM, which killed 11 people andleft one critically injured, “found internal wall thinning ondamaged pipe that was consistent with internal corrosion.” Also, it”follows a review of [pipeline] incidents involving internalcorrosion, some of which resulted in loss of life, injuries andsignificant property damage.”

Agency review of incident reports and inspections “indicatedthat better industry guidance is needed to determine the bestpractices for monitoring the potential for internal corrosion inoperator pipelines,” the OPS advisory bulletin said.

It advised gas pipelines to refer to the recommendedcorrosion-monitoring practices of the national consensus standardsorganizations, including the American Petroleum Institute, theNational Association of Corrosion Engineers, and the Gas PipingTechnology Committee (GPTC).

The OPS noted that the GPTC is considering modifying its “Guidefor Gas Transmission and Distribution Piping Systems” to addressdesign considerations, corrective measures and detection techniquesfor internal corrosion.

It recommended that gas pipelines give “special attention” to anumber of specific conditions, including flow characteristics, pipelocation (especially drips, deadlegs and sags, which are on-linesegments that are not cleaned by pigging or other methods),fittings and/or “stabbed” connections which could affect gas flow,operating temperature and pressure, water content, carbon dioxideand hydrogen sulfide content, carbon dioxide partial pressure,presence of oxygen and/or bacteria, and sediment deposits.

OPS further urged gas pipelines to focus their review onsegments downstream of gas production and storage fields, where itsaid corrosive elements most often accumulate. Also, “reviewconditions in pipeline segments with low spots, sharp bends, suddendiameter changes, and fittings that restrict flow or velocity, andsegments in unusual terrain. These features can contribute to theformation of internal corrosion by allowing condensates to settleout of the gas stream.”

For further information, contact DOT’s Richard Huriaux by phoneat (202) 366-4565 or by e-mail at richard.huriaux@rspa.dot.gov.

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