NTSB Safety Recommendation P-78-001

NTSB safety recommendation P-78-001.

INSPECT THE FIELD SAGBEND UNDER THE STREAM AND ADJACENT TO THE OVERBEND THAT FAILED AND AT ANY OTHER KNOWN LOCATIONS WHERE THE PIPELINE HAS UNDERGONE SETTLEMENT OF THIS TYPE WITH THE MAGNETIC-PARTICLE-INSPECTION OR OTHER SUITABLE TECHNIQUE, FOR SIGNS OF STRESS-CORROSION CRACKING. REPLACE THE SAGBEND OR OTHER PIPE IF INCIPIENT CRACKING IS PRESENT.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1978-02-08

Adopted Date: 1978-01-12

Overall Date Closed: 1979-03-14

Synopsis: ON JULY 20, 1977, A 12-INCH PROPANE PIPELINE, OWNED BY THE CONSOLIDATED GAS SUPPLY CORPORATION, RUPTURED NEAR THE TOWN OF RUFF CREEK, PENNSYLVANIA. THE LIQUID ESCAPED FROM THE PIPELINE, VAPORIZED, AND PROPANE VAPORS SETTLED LIKE A FOG OVER THE BOTTOM OF A VALLEY. TWO MEN IN A PICKUP TRUCK ENTERED THE PROPANE CLOUD; THE TRUCK STALLED AND THE PROPANE GAS IGNITED WHEN AN ATTEMPT WAS MADE TO RESTART THE TRUCK. THE 2 PERSONS IN THE TRUCK WERE KILLED.

Ntsbnumber: DCA77MP027

Report Number: PAR-78-01

Addressee Name: Consolidated Gas Transmission Corporation

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1979-03-14

Addressee Organization Type: P-Private Industry

Communication Date: 1978-07-17

Communication Type: Official Correspondence

Communication Contents: CONSOLIDATED GAS SUPPLY CORP. LTR: THE EXTERIOR SURFACE OF THE SAGBEND WAS INSPECTED ON 4-3-78 UTILIZING X-RAY MAGNETIC PARTICLE, DYE PENETRATION, AND VISUAL INSPECTION. THE INSPECTION WAS PERFORMED TO DETERMINE THE PRESENCE OF ANY PRIMARY OR SECONDARY TRANSVERSE CRACKS. THE TESTS SHOWED THAT NO STRESS-CORROSION CRACKING WAS PRESENT. THE VISUAL INSPECTION SHOWED THE PIPE TO BE IN VERY GOOD CONDITION. 1/23/79 CONSOLIDATED GAS SUPPLY CORP. LTR: THE SAGBEND WAS INSPECTED AND NO STRESS CORROSION CRACKING WAS FOUND. THE ENTIRE LENGTH OF LINE G-136 IS BEING WALKED AT LEAST ONCE A MONTH AND MORE FREQUENTLY IN CERTAIN AREAS SUCH AS BETWEEN I-79 AND I-70. NO GROUND SETTLEMENT HAS BEEN WITNESSED IN THE AREA OF THE PIPELINE. ELEVATION BENCH MARKS HAVE BEEN ESTABLISHED IN THE AREA OF THE FAILURE TO CHECK FOR ANY MOVEMENT OF THE PIPE OR SURROUNDING GROUND. THESE BENCH MARKS ARE BEING MONITORED ON A WEEKLY BASIS. THIS MONITORING WILL CONTINUE AND SHOULD ANY SETTLEMENT BE DISCOVERED, THE PIPE IN THAT AREA WILL BE THOROUGHLY INVESTIGATED FOR STRESS CORROSION CRACKING.

Addressee Organization Type: P-Private Industry

Communication Date: 1979-03-14

Communication Type: Official Correspondence