MO Pipeline Explosion Caused by Corrosion
Corrosion has been named the culprit behind a natural gas pipeline explosion that happened just north of Mexico, Missouri, in early March. The incident, with no reported fatalities or injuries, resulted in the destruction of a house under construction at the time.
A stress corrosion crack was named the reason for the explosion, according to a report filed by Energy Transfer Partners, which oversees the impacted Panhandle Eastern pipeline, among others. The report was filed with the Pipeline and Hazardous Materials Safety Administration, and was released earlier this month.
The explosion occurred roughly a mile north of Mexico, making a sound akin to that of a jet engine, witnesses reported. At the time of the incident, a house under construction by Matt and Shawna Penn near the pipeline was destroyed. Once the pipeline was shut down, the fire remained active for another 40 minutes.
The incident report, filed by Energy Transfer Partners with the Pipeline and Hazardous Materials Safety Administration, was released April 2. https://t.co/1dlv51qnAb— Mexico Ledger (@MexicoLedger) April 12, 2019
According to the Columbia Daily Tribune, the pipeline is composed of 30-inch diameter carbon steel pipe, with a minimum yield strength of 60,000 pounds per square inch. The Pipeline and Hazardous Materials Safety Administration is working with Energy Transfer Partners throughout the investigation process.
Collectively, Panhandle Eastern runs from the panhandle of Oklahoma, through the Midwest, carrying gas to Indiana and Ohio.
According to the Daily Tribune, pressure in the pipe did not exceed the maximum operating pressure allowance. The investigation has also not revealed any human mistakes or malfunctions from the control room.
The pipe, buried five feet underground, experienced a rupture 94 inches wide at its widest part, the total circumference running 864 inches. The 621-foot blast radius resulted in roughly $1.14 million in property damage, and around 91,719 cubic feet of natural gas was released at the time of the explosion.
The pipeline was last inspected in 2015, when a tool was used to assess the internal condition of the pipe. Testing, which involved magnetizing the pipe and keeping an eye out for deformations in the magnetic field, was also carried out to determine if there had been corrosion of the steel. The same kind of testing was also completed in 2008.
In the weeks since the incident, Energy Transfer carried out multiple hydrotests on a 15-mile length of pipeline. The testing failed four times. The fifth test was completed successfully earlier this month.
“The purpose of a hydrotest is to test the strength of the pipe using water by taking the pressure inside the pipe to a higher level than normal operations,” said Energy Transfer Public Relations Representative Amanda Gorgueiro.
“This will not only verify the integrity of repairs, it will also identify any areas we may want to proactively investigate further.”
Previously, such testing hadn’t been used since the pipeline’s installation in 1962. Roughly 16 miles of pipeline was shut down due to the rupture, and though it implements a supervisory control and data acquisition system and helped identify the damage, the rupture was originally pointed out by local operators.