ONE YEAR ANNIVERSARY OF THE HOUSTONIA, MO GAS PIPELINE EXPLOSION – STILL NO OFFICIAL INVESTIGATION REPORT, BUT THE CAUSE MUST BE THE SAME THAT CAUSED THE 2008 EXPLOSION OF THE SAME PIPELINE: CORROSION AND LACK OF MAINTENANCE
Today is the one year anniversary of the November 29, 2013
pipeline explosion at the Panhandle Eastern Pipeline Company near Hughesville,
Mo., in Pettis County. The explosion lit
up the sky for miles early Friday morning, with flames seen hundreds of feet
into the air. Residents from more than
30 miles away reported seeing the fireball in the sky. Reports out of Sedalia, which is 15 miles
from the pipeline, indicate that tremors from the blast were felt in the area.
A spokesperson from Panhandle Eastern says a 30-inch pipeline
ruptured just before midnight, causing the explosion. Panhandle Eastern Pipeline Co. is about 90
miles from Kansas City.
No injuries were reported. Three homes were evacuated, but by mid-morning
on Friday, the residents had been allowed back in.
“The gas has been rerouted from this area so there will be no
impact to customer deliveries. The
company and the appropriate regulatory agencies (Pipeline and Hazardous
Materials Safety Administration, “PHMSA”, a division of the US Department of
Transportation) will conduct an investigation into the circumstances
surrounding the incident,” wrote Vicki Granado, spokesperson for Panhandle
Eastern Pipe Line Co.
The flames and the explosion destroyed seven outlying buildings
on a nearby hog farm. Daylight showed
that the explosion left a smoldering crater. It took more than two hours to
extinguish the blaze.
Investigators are still working to determine was caused the
explosion.
In 2008, the pipeline ruptured in Houstonia, which is about 20
miles away from the scene of Friday's explosion. The 2008 explosion caused about $1 million in
damage.
Friday's explosion was heard miles away including in Sedalia,
the county seat of Pettis County and the home of the Missouri State Fair.
"I live about 12 miles away ... and I heard the explosion,"
said Pettis County Sheriff Kevin Bond. "I thought it was a nearby
residence. When I looked out, I could see the large fireball."
Gas pipeline explodes, sets fire to nearby buildings
The Pipeline and Hazardous Materials Safety Administration
(PHMSA), a division of the U.S. Department of Transportation, is working with
state and local officials to gather information on the rupture.
PHMSA spokeswoman Jeannie Shiffer said the ruptured segment of
the pipeline would be sent to an independent metallurgist for analysis and that
the agency's investigation would take several weeks.
Another Panhandle Eastern pipeline ruptured in August 2008 in
Cooper County, causing about $1 million in damages, according to a PHMSA
report. Here is the summary investigation
on that explosion in 2008.
Pipeline Failure Investigation Report for Pipeline System:
Houstonia 200 Line in 2008
Operator: Panhandle Eastern Pipeline Company, LP
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:
1) The Failure of the pipeline 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).
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.
Causes &
CONTRIBUTING FACTORS of Gas Pipeline Explosions
Extraction of oil and natural gas is a difficult and dangerous
process. To do the job safely, workers must be well trained and have the
equipment they need. Companies must continually emphasize worker safety,
maintain equipment in good working order and ensure all federal safety
regulations are met.
Safety failures in the field or at production facilities or gas
plants can cause deadly gas pipeline explosions.
Investigating the Cause of the Explosion
·
Gas pipeline explosions and throughout the
nation occur due to a number of reasons. Some of the common causes of pipeline
explosions include:
·
Improper installation, including poor welding
and failure to install emergency shut-off valves
·
Mechanical damage during excavation work
·
Defective parts, including gas connectors or
control valves
·
Failure to maintain or replace an aging natural
gas line, meter sets, joints, service lines and gas mains; failure to change
out cast iron pipelines (which can suffer metal fatigue from corrosion and
being over pressurization)
·
Failure to properly respond to consumers'
"gas leak" calls
·
Inadequate safety practices and poor training of
personnel, including failure to train and coordinate gas leak response with
local emergency response organizations and failure to qualify employees under
the mandatory "Cover Tasks" pipeline regulations
·
Failure to follow minimum pipeline safety
regulations
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