NTSB Safety Recommendation P-71-009

NTSB safety recommendation P-71-009.

NTSB RECOMMENDS THAT THE MOBIL OIL CORPORATION TAKE THE FOLLOWING ACTION: RECALCULATE THE PRESENT MAXIMUM ALLOWABLE OPERATING PRESSURE ON THIS PIPELINE, UTILIZING A JOINT FACTOR OF O.85 FOR THE ERW SECTIONS OF THE LINE, AND REDUCE THE PRESSURE AT WHICH THE LINE IS OPERATED, WHERE NECESSARY, TO COMPLY WITH THESE NEW CALCULATIONS.

Priority: CLASS II

Overall Status: Closed - Acceptable Alternate Action

Issued Date: 1971-07-01

Adopted Date: 1971-07-01

Overall Date Closed: 1976-09-10

Synopsis: ON SEPTEMBER 9, 1969, A 14-INCH PIPELINE CARRYING NATURAL GAS AT A PRESSURE OF MORE THAN 780 P.S.I.G. RUPTURED IN A RESIDENTIAL SUBDIVISION 3 1/4 MILES NORTH OF HOUSTON, TEXAS. ALL RESIDENTS WERE EVACUATED, AND ABOUT 8 TO 10 MINUTES LATER, THE ESCAPING GAS EXPLODED VIOLENTLY. THIRTEEN HOUSES, RANGING FROM 24 FEET TO 250 FEET FROM THE RUPTURE, WERE DESTROYED BY THE BLAST. THE LEAKING GAS CAUGHT FIRE AND BURNED FOR 1 1/2 HOURS UNTIL VALVES ON EITHER SIDE OF THE LEAK WERE CLOSED BY MOBIL WORKMEN. IN ALL, 106 HOUSES WERE DAMAGED, AND PROPERTY DAMAGE WAS ESTIMATED AT $500,000. MIRACULOUSLY, THERE WERE NO DEATHS, BUT 9 PEOPLE WERE INJURED, 2 SERIOUSLY.

Ntsbnumber: PLD69XR001

Report Number: PAR-71-01

Addressee Name: ExxonMobil Corporation

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-09-10

Addressee Organization Type: P-Private Industry

Communication Date: 1971-11-12

Communication Type: Official Correspondence

Communication Contents: IN A LETTER FROM MOBIL, NEW INFORMATION WAS SUPPLIED ALONG WITH A "TECHNICAL REVIEW." MOBIL REQUESTED THAT BASED ON THIS NEW DATA, THE RECOMMENDATION BE WITHDRAWN. THE TECHNICAL REVIEW IS BEING STUDIED AND A REPLY WILL BE PROPOSED. 5/30/72 - MOBIL SUBMITTED ADDITIONAL INFORMATION CONCERNING MANUFACTURING SPECIFICATIONS AND TESTS PERFORMED AND RENEWED ITS REQUEST THAT THE RECOMMENDATION BE WITHDRAWN. CORRESPONDENCE DOCUMENTATION INCOMPLETE.

Addressee Organization Type: P-Private Industry

Communication Date: 1973-04-30

Communication Type: Official Correspondence