NTSB Safety Recommendation P-92-001

NTSB safety recommendation P-92-001.

THE NTSB RECOMMENDS THAT THE OKLAHOMA NATURAL GAS COMPANY: PERIODICALLY INSPECT ALL GAS SERVICE REGULATORS INSTALLED UNDERGROUND TO DETERMINE WHETHER THE VENT LINES ARE OBSTRUCTED AND CORRECT DEFICIENT CONDITIONS IDENTIFIED.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1992-04-29

Adopted Date: 1992-04-09

Overall Date Closed: 1995-08-21

Synopsis: AT 7:02 P.M. CENTRAL STANDARD TIME ON JULY 5, 1991, AT TULSA, OKLAHOMA, HIGH-PRESSURE GAS ENTERED A LOW-PRESSURE, SINGLE-FAMILY CUSTOMER-SERVICE LINE CONNECTED TO A GAS METER AND REGULATOR IN A BURIED CONCRETE BOX NEAR THE CUSTOMER'S FRONT PROPERTY LINE. GAS AT 40-PSIG PRESSURE WAS SUPPLIED TO THE REGULATOR AND METER AT 3805 EAST 98TH STREET FROM A 2-INCH-DIAMETER PLASTIC GAS MAIN AND A 1 1/4-INCH-DIAMETER PLASTIC SERVICE LINE. THE HIGH-PRESSURE GAS ENTERED THE GAS FUEL LINES AND APPLIANCES RESULTING IN THE ESCAPE OF GAS INTO THE HOUSE. THERE WERE NO INJURIES, BUT THE GAS ESCAPING FROM THE FURNACES AND THE WATER HEATER IGNITED AND FUELED FIRES THAT DESTROYED THE MULTILEVEL HOUSE. PROPERTY DAMAGE WAS ESTIMATED BY THE TULSA FIRE DEPARTMENT AT 540,000.

Probable Cause: Failure to ensure that the gas service regulator safety relief valve was adjusted properly

Ntsbnumber: DCA91FP009

Report Number: None

Addressee Name: Oklahoma Natural Gas Corporation

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1995-08-21

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1995-08-21

Communication Type: Official Correspondence

Communication Contents: P-92-001 URGED THE ONGC TO PERIODICALLY INSPECT ALL GAS SERVICE REGULATORS INSTALLED UNDERGROUND TO DETERMINE WHETHER THE VENT LINES ARE OBSTRUCTED & CORRECT DEFICIENT CONDITIONS IDENTIFIED. THE BOARD NOTES THAT THE ONGC INSPECTED ALL DOMESTIC UNDERGROUND REGULATORS IN AUGUST 1992, IDENTIFIED UNDERGROUND REGULATORS IN DEFICIENT CONDITIONS, & MOVED THESE ABOVE GROUND. THE ONGC HAD ALSO IMPLEMENTED A PERIODIC INSPECTION PROGRAM & ANTICIPATED RELOCATING MOST, IF NOT ALL, SETTINGS ABOVE GROUND. BASED ON THIS INFO, P-92-1 HAS BEEN CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1995-06-19

Communication Type: Official Correspondence

Communication Contents: A PERIODIC INSPECTION PROGRAM IS IN PLACE AS RECOMMENDED. CORRECTIVE ACTION HAS BEEN TAKEN TO ELIMINATE IDENTIFIED DEFICIENT CONDITIONS. WITHIN ON MONTH AFTER THE INCIDENT, WHICH OCCURRED ON 7/5/91, WE PERFORMED INSPECTIONS ON ALL DOMESTIC UNDERGROUND REGULATORS. A FEW REGULATORS WERE FOUND TO BE IN A LOCATION WHERE DIRT & WATER COULD EASILY ENTER THE METER & REGULATOR BOX. WE IMMEDIATELY MOVED THOSE METERS & REGULATORS ABOVEGROUND TO ELIMINATE THE POSSIBILITY OF DIRT PLUGGING THE REGULATOR VENTS. A PROGRAM IS UNDER WAY TO MOVE MOST, IF NOT ALL, UNDERGROUND SETTINGS ABOVEGROUND. OUR FIRST CHOICE IS TO RELOCATE METERS & REGULATORS ABOVEGROUND.

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1992-07-16

Communication Type: Official Correspondence