NTSB Safety Recommendation P-92-021

NTSB safety recommendation P-92-021.

THE NTSB RECOMMENDS THAT THE CONSUMERS POWER COMPANY: IMPLEMENT PROCDURES, SUCH AS THE ELIMINATION OR THE REDUCTION OF THE PIPELINE PRESSURE TO A SAFE LEVEL, TO PREVENT THE UNINTENDED SEPARATION OF PIPELINE SEGMENTS FROM KNOWN OR UNKNOWN NEARBY UNANCHORED COMPRESSION COUPLINGS WHEN PIPE IS EXCAVATED OR REMOVED.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1992-07-08

Adopted Date: 1992-06-19

Overall Date Closed: 1992-12-08

Synopsis: ABOUT 12:00 NOON EASTERN DAYLIGHT SAVINGS TIME ON JULY 17, 1991, WORKERS WERE REMOVING A CORRODE SEGMENT OF THE CONSUMERS POWER COMPANY'S (CP) 10-INCH-DIAMETER TRANSMISSION LINE PIPELINE AT BAILEY BRIDGE ROAD IN MAPLETON, MICHIGAN. AS A SEGMENT OF THE PIPELINE WAS BEING REMOVED, NATURAL GAS AT 360-PSIG PRESSURE EXERTED ABOUT 12 TONS OF FORCE ON AN ADJACENT CLOSED VALVE (H-143) CAUSING IT AND A SHORT SEGMENT OF CONNECTED PIPE TO MOVE AND SEPARATE FROM AN UNANCHORED COMPRESSION COUPLING. THE FORCE OF THE ESCAPING GAS KILLED ON WORKER (A WELDER), INJURED FIVE OTHER WORKERS, AND COLLAPSED A STEEL PIT THAT HOUSED VALVE H-143.

Probable Cause: None

Ntsbnumber: DCA91FP010

Report Number: None

Addressee Name: Consumers Power Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1992-12-08

Addressee Acronym: CMS

Addressee Organization Type: P-Private Industry

Communication Date: 1992-12-08

Communication Type: Official Correspondence

Communication Contents: THE BOARD UNDERSTANDS THAT THE CP HAS EXPANDED ITS WRITTEN PROCEDURE TO INCLUDE THE REPLACEMENT OF HIGH-PRESSURE MAIN & 4-INCH & LARGER MEDIUM-PRESSURE MAINS THAT MAY CONTAIN COMPRESSION COUPLINGS, AS WELL AS THE EVALUATION OF LOWERING THE SYSTEM OPERATING PRESSURE, WHERE FEASIBLE. THE CP HAS ALSO DEVELOPED NEW WORK METHODS TO PREVENT WORKER INJURY SHOULD A PULLOUT OCCUR WHEN REPLACING MAIN THAT MAY CONTAIN COMPRESSION COUPLINGS. BASED ON THIS INFORMATION, RECOMMENDATION P-92-21 HAS BEEN CLASSIFIED AS "CLOSED--ACCEPTABLE ACTION."

Addressee Acronym: CMS

Addressee Organization Type: P-Private Industry

Communication Date: 1992-09-25

Communication Type: Official Correspondence