Pilot Grove, MO PEPL explosion 2008-08-25

Not in a High Consequence Area (HCA)? 300x225 8/26/08 #13 -Different view of the possible failure origin after the pipe was turned over., in Pilot Grove, MO PEPL explosion, by John S. Quarterman, for SpectraBusters.org, 25 August 2008 Then a pipeline explosion may not even rate pictures on the news, even if your house or field or forest or river is what explodes. That’s what happened near Pilot Grove, Missouri 25 August 2008 on the Panhandle Eastern Pipeline 200 Line.

PHMSA, the so-called Pipeline and Hazardous Materials and Safety Administration, doesn’t actually know when the “impressed curent cathodic protection system” was energized, and doesn’t have the results of the last hydrostatic test, which was in 1955, 53 years before the pipeline corroded until it exploded. PHMSA’s Administrator just resigned, after continuing to let pipeline companies set the very definitions of accidents. Do you want to trust your air, water, property values, or safety to such an industry or such an agency?

Dennis Rich reported for the Sedalia Democrat 29 November 2013, Pipeline explodes near Hughesville,

Another Panhandle Eastern pipeline in the area ruptured on Aug. 25, 2008, near Pilot Grove in Cooper County and caused $1,046,359 in damages, according to a company pipeline failure investigation report.

Actually, it was the same Houstonia 200 Line that later blew up in 2013, according to PHMSA’s Pipeline Failure Investigation Report,

Panhandle Eastern Pipeline Company (PEPL) experienced failure of the Houstonia 200 line near Mile Post 21.6. There were no evacuations, road closings, fires, injuries or fatalities as a result of the failure. The failure did not occur in a high consequence area (HCA).

300x225 8/25/08 #10 -View of coupling ejected from pipeline., in Pilot Grove, MO PEPL explosion, by John S. Quarterman, for SpectraBusters.org, 25 August 2008 The failure occurred on August 25, 2008, at approximately 8:51 a.m. CDT. The failure is located on a rocky hillside in a rural area west of Pilot Grove, Missouri in Cooper County. The failure was identified by PEPL when Houston Gas Control detected a pressure drop in the Houstonia 200 Line. The failure was located at approximately 9:00 a.m. when a PEPL field technician reported gas blowing near Mile Post 21.6. PEPL isolated the segment at approximately 9:30 a.m., by manually closing mainline valves 2 Gate and 3 Gate. The distance between 2 Gate and 3 Gate is approximately 16 miles.

300x388 Diagram: Pilot Grove explosion, in Pilot Grove, MO PEPL explosion, by John S. Quarterman, for SpectraBusters.org, 25 August 2008 The pipeline experienced a longitudinal rupture in the pipe body. The rupture created a 50 feet by 33 ft by 7 feet deep crater in the ground. Two pipeline segments totalling 28 feet in length and a coupling were ejected from the crater a distance up to 300 feet from the rupture site. The failure origin was a 16 inch long area of reduced wall thickness located at the 6:00 orientation.

300x134 8/25/08 â?? #1- views looking West at the crater caused by the Houstonia 200 failure. (top with pipe), in Pilot Grove, MO PEPL explosion, by John S. Quarterman, for SpectraBusters.org, 25 August 2008 The portion of the pipeline containing the failure is comprised of 24-inch diameter by 0.281-inch wall thickness, API 5L-X48, manufactured by A.O. Smith and contains a longitudinal electric flash welded (EFW) seam. The reported maximum allowable operating pressure (MAOP) is 800 psig, which corresponds to 71% of the specified minimum yield strength (SMYS). The pressure at the time and location of failure was 795 psig, which corresponds to 70% of the SMYS (99% of MAOP). The MAOP was established in accordance with 192.619 ( c ), the highest actual operating pressure to which the segment was subjected during the five years preceding July 1, 1970. A hydrostatic test of the pipeline was performed in 1955. Details of the hydrostatic test are unknown.

300x173 Figure 2. Photograph of Pipe Segment B1 in the as-received condition., in Pilot Grove, MO PEPL explosion, by John S. Quarterman, for SpectraBusters.org, 25 August 2008 The pipeline, installed in 1937, is joined by circumferential girth welds and Dresser couplings. The pipeline external coating is coal tar. The pipeline has an impressed curent cathodic protection system that was reportedly energized in 1955.

The findings of PEPL’s investigation are as follows:

  1. The failure occurred due to tensile overload at a region of wall thinning caused by external corrosion.
  2. The maximum wall loss measured at the rupture surface was 0.21 inches depth (75% of wall thickness).

300x225 Figure 12. Light photomicrograph of the typical base metal microstructure from Mount M2 (4% Nital Etchant)., in Pilot Grove, MO PEPL explosion, by John S. Quarterman, for SpectraBusters.org, 25 August 2008 PEPL submitted a return to service plan to PHMSA that included a temporary 20% pressure reduction and remediation of anomalies found in a high resoultion MFL tool run. They subsequently remediated 30 anomalies with RPR less than 1.15 and replaced 912 feet of pipe. On 12/19/2009 the temporary pressure restriction was removed.

-jsq

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