NTSB Safety Recommendation P-92-005

NTSB safety recommendation P-92-005.

THE NTSB RECOMMENDS THAT THE OKLAHOMA NATURAL GAS COMPANY: INSTALL EXCESS FLOW VALVES ON NEW AND RENEWED SINGLE CUSTOMER RESIDENTIAL HIGH-PRESSURE SERVICES THAT HAVE OPERATING CONDITIONS COMPATIBLE WITH THE RATED PARAMETERS OF AT LEAST ONE MODEL OF COMMERCIALLY AVAILABLE EXCESS FLOW VALVE.

Priority: CLASS II

Overall Status: Closed - Acceptable Action

Issued Date: 1992-04-29

Adopted Date: 1992-04-09

Overall Date Closed: 2002-09-26

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

Keywords: Excess Flow Valves

Ntsbnumber: DCA91FP009

Report Number: None

Addressee Name: Oklahoma Natural Gas Corporation

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 2002-09-26

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 2002-09-26

Communication Type: Official Correspondence

Communication Contents: Because the ONGC has taken action as requested and revised its internal operating policies to require the installation of EFVs at company cost, Safety Recommendation P-92-5 is classified "Closed--Acceptable Action."

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1995-08-21

Communication Type: Official Correspondence

Communication Contents: THE BOARD WAS UNABLE TO DETERMINE THE DAMAGE TO THE CUSTOMER'S GAS FUEL LINES AND APPLIANCES CAUSE BY THE OVERPRESSURE CONDITION VERSUS THE DAMAGE LATER CAUSED BY HEAT & FIRE. CONSEQUENTLY, WE ARE INTERESTED IN REVIEWING THE ASSUMPTIONS MADE DURING THE SIMULATION, THE SUPPORT FOR THOSE ASSUMPTIONS, THE REPORT ON YOUR EVALUATION & CONCLUSION. THE AMERICAN GAS ASSOCIATON, THE AMERICAN PUBLIC GAS ASSOCIATION, & THE BOARD HAVE DEVELOPED A JOINT POSITION OF SUPPORT FOR USING EXCESS FLOW VALVES & FOR INITIATING A DATA COLLECTION PROGRAM TO DEFINE THE COSTS & BENEFITS OF EXCESS FLOW VALVE USE. CONSIDERING THE AGA & THE APGA SUPPORT FOR EXCESS FLOW VALVE USE, BHE BOARD BELIEVES THAT THE ONGC SHOULD REASSESS USING EXCESS FLOW VALVES TO PROVIDE PROTECTION FOR BOTH COMPANY EMPLOYEES & THE PUBLIC. PENDING YOUR SUBSEQUENT CONSIDERATION & REPLY, P-92-5 IS CLASSIFIED "OPEN--AWAIT RESPONSE."

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1995-12-12

Communication Type: Official Correspondence

Communication Contents: THE BOARD NOTES THAT RULE CHANGES ON RESPONSIBILITY FOR SERVICE LINE ARE PENDING IN OKLAHOMA. ADDITIONALLY, BECAUSE OF THE CURRENT UNCERTAINTY CONCERNING STATE POSITIONS ON EFVS & PENDING REGULATIONS FROM THE RSPA ON EFVS, P-92-5 IS CLASSIFEID "OPEN--AWAIT RESPONSE." PLEASE PROVIDE US WITH PERIODIC REPORTS ON PROGRESS IN THIS AREA.

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 2002-07-10

Communication Type: Official Correspondence

Communication Contents: Letter Mail Controlled 07/31/2002 3:33:07 PM MC# 2020729 After the institution of U.S. Department of Transportation regulations on excess flow valves (EFVs), Oklahoma Natural Gas Company (ONG) chose to revise its internal operating policies to require the installation of EFVs at company cost. As was mentioned in earlier correspondence, ONG had anticipated the Oklahoma Corporation Commission's rules with respect to ONG's responsibility for service line ownership and to preferred meter location (at the building) would change. These rules did change and were effective in October 1999 and January 2000, respectively. Please let us know if you require further information.

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1995-06-19

Communication Type: Official Correspondence

Communication Contents: WE HAVE EVALUATED AN AVAILABLE EXCESS FLOW VALVE & HAVE CONCLUDED THAT AN EXCESS FLOW VALVE WOULD NOT HAVE STOPPED FLOW UNDER THE CONDITIONS PRESENT AT THE TIME OF THIS INCIDENT. A STIMULATION OF THE FAILURE WAS MADE IN OUR SHOP, & FLOW AT THE TIME OF THE INCIDENT WAS BELOW THE THRESHOLD LEVEL OF THE EXCESS FLOW VALVE. WE HAVE CHOSEN TO ELIMINATE THE TYPE OF REGULATORS & THE CONDITIONS WHICH CASUSED THIS INCIDENT.

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1995-09-14

Communication Type: Official Correspondence

Communication Contents: OKLAHOMA NATURAL DOES NOT QUESTION THE ADVISABILITY OF INSTALLING EXCESS FLOW VALVES ON SERVICES THAT RUN MEDIUM PRESSURE GAS TO THE CUSTOMER'S BUILDING. HOWEVER, OKLAHOMA NATURAL'S SERVICE POINT IS AT THE CUSTOMER'S PROPERTY LINE, & WE HAVE A VERY LOW PERCENTAGE OF SERVICES AT THE CUSTOMER'S BUILDING. OUR FIRST PRIORITY IS THE REPLACEMENT OF REGULATION EQUIPMENT THAT HAS LIMITED RELIEF CAPACITY. WE HAVE DETERMINED THE ROOT CAUSE OF THESE INCIDENT WERE DUE TO OVERPRESSURE, & WE BELIEVE THAT OUR FIRST RESPONSIBILITY IS TO ELILMINATE THE FIRST OFFENDER, AS HAS BEEN REPORTED IN OUR RESPONSE. THE FLOW TEST THAT WE PERFORMED ON THE REGULATOR INVOLVED IN THIS INCIDENT PROVED THE REGULATOR DID NOT PROVIDE OVERPRESSURE PROTECTION, BUT DID LIMIT FLOW TO BELOW THE TRIP POINT OF TAHE EXCESS FLOW VALVE WHICHWAS USED IN THE TEST. THE SAME RESULT HAVE BEEN OBSERVED ON OTHER INCIDENTS WHERE OVERPRESSURE DUE TO REGULATOR DAMAGE RESULTED ON OTHER INCIDENTS WHERE OVERPRESSURE DUE TO REGULATOR DAMAGE RESULTED IN A FIRE OR OTHER DAMAGE. CURRENT RULE CHANGES ARE PENDING IN THE STATE OF OKLAHOMA THAT COULD CHANGE THE SERVICE LINE FROM THE CUSTOMER'S RESPONSIBILITY TO THE UTILITIES' RESPONSIBILITY. ADDITIONAL REGULATIONS ARE PENDING FROM THE RSPA OF THE DEPARTAMENT OF TRANSPORTATION THAT COULD MANDATE CUSTOMER NOTIFICATION & PERFORMANCE STANDARDS CONCERNING EXCESS FLOW VALVES. OUR POLICIES REGARDING THE INSTALLATION OF EXCESS FLOW VALVES WILL NOT BE DEVELOPED UNTIL THE REGULATIONS AT THE STATE & FEDERAL LEVEL HAVE BEEN FINALIZED.

Addressee Acronym: Oneok

Addressee Organization Type: P-Private Industry

Communication Date: 1992-07-16

Communication Type: Official Correspondence