NTSB Safety Recommendation P-76-050

NTSB safety recommendation P-76-050.

REVISE THE COMPANY'S WRITTEN PROCEDURES TO INCLUDE THE MAXIMUM LENGTH OF PLASTIC PIPE TO BE USED WITH COMPRESSION COUPLINGS, THE NUMBER OF FOOT-POUNDS OF TORQUE REQUIRED FOR EACH SIZE OF COMPRESSION COUPLING, A TIME INTERVAL DURING CONSTRUCTION BETWEEN RETORQUING OF COUPLINGS, AND THE TYPE OF STIFFENER TO BE USED WITH EACH BRAND OF COUPLING.

Priority: CLASS II

Overall Status: Closed - Acceptable Alternate Action

Issued Date: 1976-09-15

Adopted Date: 1976-07-07

Overall Date Closed: 1980-08-12

Synopsis: ON JANUARY 10, 1976, GAS WHICH WAS LEAKING INTO THE PATHFINDER HOTEL, IN FREMONT, NEBRASKA, IGNITED. THE GAS WAS LEAKING FROM A 2-INCH PLASTIC PIPE WHICH HAD PULLED OUT OF ITS COMPRESSION COUPLING; THE GAS SEEPED INTO THE HOTEL BECAUSE IT HAD BEEN CAPPED ABOVE BY FROZEN EARTH AND A CONCRETE ROAD SURFACE. THE HOTEL EXPLODED AND FIRE ENSUED; THE EXPLOSION AND FIRE DESTROYED THE HOTEL, DAMAGED NEARBY BUILDINGS, AND BROKE WINDOWS WITHIN A ONE-BLOCK RADIUS. THIRTY-NINE PERSONS WERE INJURED AND 20 PERSONS WERE KILLED.

Ntsbnumber: DCA76MP013

Report Number: PAR-76-06

Addressee Name: Nebraska Natural Gas Company

Addressee Status: Closed--No Longer Applicable

Addressee Date Closed: 1980-08-12

Addressee Organization Type: P-Private Industry

Communication Date: 1978-05-22

Communication Type: Official Correspondence

Communication Contents: NEBRASKA NATURAL GAS COMPANY LTR: WE PRESENTLY FOLLOW A POLICY THAT WAS ESTABLISHED WITHIN A FEW DAYS FOLLOWING THE ACCIDENT OF CONNECTING PLASTIC DISTRIBUTION MAINS AND SERVICES TO STEEL IN THE FOLLOWING MANNER. WE FUSE A TRANSITION (PLASTIC TO STEEL) FITTING TO THE PLASTIC PIPE. WE THEN WELD THE STEEL TO STEEL OR CONNECT THE STEEL TO STEEL WITH A COMPRESSION COUPLING. IF A COMPRESSION COUPLING IS USED, WE, IN ALL APPLICATIONS, SPOT WELD, ELECTRICALLY, A 3/4" STEEL STRAP FROM THE EXISTING STEEL MAIN TO THE STEEL PORTION OF THE TRANSITION FITTING, THUS PROVIDING A POSITIVE ANCHOR TO ELIMINATE EVERY LIKELIHOOD OF A JOINT SEPARATION. THE JOINT IS CATHODICALLY BONDED AND WRAPPED TO INSURE ITS LONGEVITY. WE HAVE CHECKED 99 PERCENT OF THE CONNECTIONS IN OUR SYSTEM COMPANY-WIDE ON PIPE SIZES ABOVE 1" TO INSURE THAT NO FURTHER PULLOUTS OCCUR. 6/19/80 - NEBRASKA NATURAL GAS COMPANY LTR: AS WAS NOTED IN OUR PREVIOUS COMMUNICATION TO THE BOARD, 5/22/78, THE USE OF COMPRESSION COUPLINGS INCLUDES A WELDED STRAPPING PROCEDURES TO SECURE THE COMPRESSION COUPLING AND ELIMINATE THE POSSIBILITY OF A PULL OUT OWING TO CONTRACTION OF PIPE. THE COMPANY HAS SINCE ADDED TO PROCEDURE THE USE OF THE AMP-FIT FITTING FOR JOINING PIPE IN PLASTIC TO PLASTIC AND PLASTIC TO STEEL APPLICATIONS AND IS ALSO USING THE NORMAC LOCK STIFFENER FOR JOINING 3/4" AND 1" SERVICES TO STEEL MAIN TAPS. THE USE OF THE AMP-FIT AND NORMAC FITTING IS ALSO COVERED IN WRITTEN PROCEDURE AND QUALIFICATION TESTING.

Addressee Organization Type: P-Private Industry

Communication Date: 1980-08-12

Communication Type: Official Correspondence