Exxon points to rare chemical mix as Pegasus flaw | Arkansas Blog

Tuesday, April 1, 2014

Exxon points to rare chemical mix as Pegasus flaw

Posted By on Tue, Apr 1, 2014 at 5:03 PM

Exxon issued a  Monday of the remedial work plan it submitted to the federal agency that regulates pipeline over the weekend on the Pegasus pipeline, which expands upon its earlier finding that a manufacturing defect in the low-frequency electric resistance weld pipe (ERW) caused the joint crack that sent 210,000 gallons of crude oil spewing into a Mayflower neighborhood last year. Exxon's summary now says that "atypical pipe properties [are] the most significant contributing factor" to the break." Company vice president Karen Tyrone, vice president of Exxon Mobil Pipeline Co.,  also referred to the joint's "extreme metallurgical properties" in an interview with Talk Business.

By putting the focus on the atypical properties — a chemical stew of sulfur, manganese and carbon company officials say they've never seen to such an extent in a joint before — and away from a well-known manufacturing defect of the ERW pipe used in the northern section that includes Arkansas, it would seem that Exxon is casting the rupture as caused by a rare flaw.

Does Exxon believe that the atypical chemical properties in the 648-mile pipeline only occur in Mayflower? 
 
Richard Kuprewicz of Accufacts Inc., a pipeline safety consultant working with Central Arkansas Water, which would like to see Exxon move the pipe away from Little Rock's drinking water supply, said that ERW pipe can have "some strange chemistry" that might contribute to pipe failure; the industry is used to seeing strange chemistry in certain batches of pipe. He acknowledged that he has not seen the chemical makeup in the section of pipe that Exxon has seen, and that it could indeed be higher than elsewhere.

Exxon also announced it would conduct a spike hydrostatic test along the line, which involves shooting water through the pipe above its maximum operating pressure to test for weaknesses. If the pipe fails in a few places, pipe can be replaced. If it fails all along the line, one would think the pipe should be abandoned.

The Exxon summary said the test would be performed at a higher-than-maximum operating pressure to detect leaks. "The devil is in the details" on how the test is performed, Kuprewicz said. "What is your pressure range? That is the real key."

Exxon conducted hydrostatic testing along the pipeline in 2005 and 2006. Yet the Pegasus failed at below the maximum operating pressure. "Something happened to cause the imperfection" in the ensuing years, Kuprewicz said, though because he is an impartial party, he declined to speculate what. "The important thing is that [Exxon is] heading in a positive direction." 


Tags: , , , , , ,


Favorite

Comments (4)

Showing 1-4 of 4

Add a comment

 
Subscribe to this thread:
Showing 1-4 of 4

Add a comment

More by Leslie Newell Peacock

  • LIVE LIFE CHILL NOT DEAD DONE GONE

    Contrary to rumor, Live Life Chill, the bar/restaurant in the erstwhile Revolution Taco and Tequila Lounge space at the corner of Cantrell and President Clinton Avenue, is not closed. Service manager Lindsey McFadin called the Times this afternoon to say a rumor the bar had closed was killing business; by 3 p.m., no one had been in. The Times, too, had heard the rumor from a number of sources. What has changed, McFadin said, is that the bar is now only open from 11 a.m. to 2 a.m. Friday and Saturday and 10 a.m. to 3 p.m. Sunday.
    • Nov 16, 2018
  • New gallery for SoMa: M2

    M2 Gallery, located for 12 years in the Pleasant Ridge Shopping Center, has made the move to 1300 Main St. in the hopping SoMa neighborhood and will hold its Grand (Re)opening from 5-8 p.m. Nov. 30.
    • Nov 16, 2018
  • Entergy agrees to end coal-burning in Arkansas in Sierra Club settlement

    Under a settlement agreement filed in federal court today, Entergy Arkansas has agreed to quit burning coal at its White Bluff plant by the end of 2028, its Independence plant by the end of 2030 and to shutter its remaining operating plant at Lake Catherine by the end of 2027.
    • Nov 16, 2018
  • More »

Readers also liked…

Slideshows

  • Arkansas vs Ole Miss at War Memorial stadium in Little Rock, Saturday, Oct. 13, 2018. After leading for much of the game, Arkansas lost 37-33 when Ole Miss scored the game winning Touchdown with less that 2 minutes left. 
  • Margaret Clark Adventure Park
    New sculptures, preschoolers play area dedicated in Riverfront Park in Little Rock.

Most Recent Comments

 

© 2018 Arkansas Times | 201 East Markham, Suite 200, Little Rock, AR 72201
Powered by Foundation