NTSB Safety Recommendation P-70-024

NTSB safety recommendation P-70-024.

THE NTSB RECOMMENDS THAT ALL STATES, THE DISTRICT OF COLUMBIA, AND PUERTO RICO TAKE THE FOLLOWING ACTION: INCLUDE IN THEIR STANDARDS A REQUIREMENT THAT RELIEF DEVICES BE PROVIDED FOR LOW-PRESSURE DISTRIBUTION SYSTEMS WHICH COULD BE OVERPRESSURED BY INTERCONNECTED HIGH-PRESSURE GAS. IF RELIEF DEVICES WOULD PRESENT A HAZARD, AN AUTOMATIC SHUTOFF DEVICE SHOULD BE INSTALLED AT EACH UNPROTECTED SOURCE OF HIGH-PRESSURE GAS. IT IS NOT INTENDED THAT THIS RECOMMENDATION APPLY TO HIGH-PRESSURE GAS CONNECTED TO A LOW-PRESSURE SYSTEM BY MEANS OF A REGULATOR STATION PROVIDED WITH A SUITABLE DEVICE TO PREVENT ACCIDENTAL OVERPRESSURING.

Priority: CLASS II

Overall Status: Closed--No Longer Applicable

Issued Date: 1969-12-04

Adopted Date: 1969-12-04

Overall Date Closed: 1976-07-20

Synopsis: ON JUNE 3, 1969, A SERIES OF EXPLOSIONS AND FIRES OCCURRED IN THE NATURAL GAS DISTRIBUTION SYSTEM IN THE WESTERN HALF OF THE GLEN PARK RESIDENTIAL SUBDIVISION OF GARY, INDIANA. THERE WERE NO FATALITIES, BUT NINE RESIDENTS AND FIVE FIREMEN WERE INJURED. SEVEN HOUSES WERE DESTROYED, AND 45 OTHERS INCURRED DAMAGE EXTENDING FROM MINOR TO VIRTUAL DESTRUCTION. TOTAL PROPERTY DAMAGE WAS ABOUT $350,000.

Probable Cause: The Board finds that the probable cause of this accident was a combination of personnel error and system inadequacy. Involved were the inadvertent opening of a separation valve by a gas company employee allowing gas at 20 p.s.i.g. to flow into a 1/4 p.s,i,g. system and a system which could not control adequately such an increase in pressure owing to the lack of overpressure protection devices. Thereafter, the increase in pressure caused the failure of a regulator diaphragm which allowed an 80-fold overpressure in the low-pressure system to become continuous for 30 - 45 minutes. Significant contributing causal factors were: 1. The inaccessibility of the shutoff valve for the regulator which failed. 2. The lack of systematic review of the hazards in the conversion operation which could have revealed the hazardous condition in which one human error could produce catastrophe, coupled with the lack of a written plan for conversion. 3. The absence in Code B31.8 of any specification of safeguards to be employed at separation (isolation) valves during pressure conversions. 4. The lack of complete leakage surveys, before and during the pressure increase in the eastern area, which would have probably disclosed and leaking condition of the pipe and avoided the major leaks which occurred on June 3, 1969.

Ntsbnumber: DCA69FP004

Report Number: PAR-UNNUMBERED

Addressee Name: State of Wyoming

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of West Virginia

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Washington

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: Commonwealth of Virginia

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Vermont

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Utah

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Texas

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Tennessee

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of South Dakota

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of South Carolina

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Rhode Island

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: Commonwealth of Pennsylvania

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Oregon

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Oklahoma

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Ohio

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of North Dakota

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of North Carolina

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of New York

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of New Mexico

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of New Jersey

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of New Hampshire

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Nevada

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Nebraska

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Montana

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Missouri

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Mississippi

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Minnesota

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Michigan

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: Commonwealth of Massachusetts

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Maryland

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Maine

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Louisiana

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: Commonwealth of Kentucky

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Kansas

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Iowa

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Indiana

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Illinois

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Idaho

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Hawaii

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Georgia

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Florida

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Delaware

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Connecticut

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Colorado

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of California

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Arkansas

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Arizona

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Alaska

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: State of Alabama

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: Commonwealth of Puerto Rico

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20

Addressee Name: District of Columbia

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1976-07-20