Not in a High Consequence Area (HCA)?
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”
and doesn’t have the results of the last hydrostatic test,
which was in 1955, 53 years before the pipeline corroded until it exploded.
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?
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
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).
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.
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.
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.
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:
The failure occurred due to tensile overload at a region of wall thinning caused by external corrosion.
The maximum wall loss measured at the rupture surface was 0.21 inches depth (75% of wall thickness).
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.