NTSB Safety Recommendation P-92-016

NTSB safety recommendation P-92-016.

THE NTSB RECOMMENDS THAT THE PACIFIC GAS AND ELECTRIC COMPANY: INSTALL EXCESS FLOW VALVES ON NEW AND RENEWED HIGH-PRESSURE, SINGLE-CUSTOMER RESIDENTIAL GAS SERVICE LINES AT OR NEAR THEIR CONNECTIONS TO THE GAS MAIN.

Priority: CLASS II

Overall Status: Closed - Unacceptable Action

Issued Date: 1992-05-21

Adopted Date: 1992-05-05

Overall Date Closed: 1995-12-12

Synopsis: ABOUT 4:26 A.M. ON DECEMBER 28, 1991, TWO EXPLOSIONS IN RAPID SUCCESSION OCCURRED IN APARTMENT NO. 3 OF A TWO-STORY, EIGHT-APARTMENT, WOOD-FRAME STRUCTURE AT 631 SPENCER STREET, SANTA ROSA, CALIFORNIA. FIRE AFTER THE EXPLOSIONS DESTROYED THAT APARTMENT AND THREE OTHER APARTMENTS IN THE FRONT OF THE BUILDING. TWO PEOPLE WERE KILLED AND THREE OTHERS WERE INJURED. THE ONLY GAS APPLIANCE IN THE APARTMENT BUILDING WAS A HOT WATER HEATER IN A REAR APARTMENT. IT REMAINED UNDAMAGED BY THE EXPLOSIONS OR FIRE. NONE OF THE BUILDING RESIDENTS REPORTED SMELLING THE ODORANT THAT IS ADDED TO NATURAL GAS, BUT LATER TESTS SHOWED THAT THE ODORANT LEVEL MET FEDERAL REQUIREMENTS.

Probable Cause: None

Keywords: Excess Flow Valves

Ntsbnumber: DCA92FP002

Report Number: None

Addressee Name: Pacific Gas and Electric Company

Addressee Status: Closed - Acceptable Action

Addressee Date Closed: 1995-12-12

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1992-11-23

Communication Type: Official Correspondence

Communication Contents: THE BOARD AGREES THAT STANDARDS SHOULD BE DEVELOPED FOR THE MANUFACTURING, INSTALLATION, & PERFORMANCE OF EFVS. THEREFORE, WE ARE PLEASED TO LEARN THAT THE pg&e IS CONDUCTING AN EVALUATION OF THE POTENTIAL BENEFITS & IMPACTS OF EFVS IN VARIOUS APPLICATIONS, & WE WOULD APPRECIATE RECEIVING THE RESULTS OF THAT EVALUATION. HOWEVER, THE BOARD NOTES THAT ONE MILLION EFVS OF CURRENT DESIGNS HAVE BEEN OPERATING IN SEVERAL GAS SYSTEMS, (FOR EXAMPLE, EAST OHIO GAS COMPANY) FOR MANY YEARS & HAVE PRODUCED POSITIVE RESULTS. THE PG&E SHOULD CONTACT THE OPERATORS OF THOSE GAS SYSTEMS TO LEARN OF THE CRITERIA THEY HAVE IMPLEMENTED FOR THE USE OF EFVS & THEN DEVELOP A SIMILAR POLICY ON USING EFVS. IN SO DOING, THE PG&E COULD QUICKLY ESTABLISH A POLICY ON THE USE OF EFVS, WITHOUT DUPLICATING TESTS ALREADY PERFORMED, WHILE IT CONTINUES TO ASSESS OTHER CONDITIONS & LOCATIONS WHERE EFVS COULD BE EFFECTIVE. PENDING FURTHER RESPONSE, RECOMMENDATION P-92-016 WILL BE CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1995-12-12

Communication Type: Official Correspondence

Communication Contents: THE BOARD IS EXTREMELY DISAPPOINTED WITH PG&E'S DECISION NOT TO INSTALL RECENTLY DECIDED NOT TO REQUIRE USE OF EFVS, THERE ARE MANY EFV SUPPORTERS, INCLUDING THE AMERICAN GAS ASSOCIATION & THE AMERICAN PUBLIC GAS ASSOCIATION. TOGETHER, THESE ASSOCIATIONS REPRESENT ALMOST ALL OF THE NATION'S APPROXIMATELY 1,400 GAS DISTRIBUTION PIPELINE OPERATORS. THE BOARD CONTINUES TO BELIEVE THAT EFVS PROVIDE INCREASED SAFETY FOR GAS CUSTOMERS & THE PUBLIC. P-92-16 HAS BEEN CLASSIFIED "CLOSED--UNACCEPTABALE ACTION."

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1992-08-31

Communication Type: Official Correspondence

Communication Contents: WE AND OTHER CALIFORNIA GAS UTILITIES, ALONG WITH THE CALIFORNIA PUBLIC UTILITIES COMMISSION (CPUC), CONTINUE TO OPPOSE THE WIDESPREAD INSTALLATION OF EXCESS FLOW VALVES AT THIS TIME FOR SEVERAL REASONS. FIRST, WE BELIEVE THAT THERE IS INADEQUATE BENEFIT FOR THE COST. THE CALIFORNIA GAS UTILITIES IN CLOSE COORDINATION WITH THE CPUC ARE EMBARKING ON A PROGRAM TO MORE EXTENSIVELY EVALUATE EFVS, INCLUDING WORK TO: EVALUATE POTENTIAL BENEFITS IN VARIOUS APPLICATIONS, EVALUATE POTENTIAL IMPACTS, POSITIVE AND NEGATIVE, OF EXTENSIVE USE OF EFVS IN SEISMICALLY ACTIVE AREAS. DETERMINE IMPACTS ON SYSTEM OPERATION AND MAINTENANCE ACTIVITIES AND HOW TO HANDLE THOSE IMPACTS. DEFINE SERVICE DESIGN CRITERIA NEEDED TO MAXIMIZE THE EFFECTIVENESS OF EFVS.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1995-09-18

Communication Type: Official Correspondence

Communication Contents: PG&E REMAINS OPPOSED TO THE WIDESPREAD INSTALLATION OF EFV FOR THE SAME REASONS GIVEN IN THE 1992 COMMENTS ON RECOMMENDATIONS. FIRST, PG&E BELIEVES THAT THERE IS INADEQUATE BENEFIT FOR THE COST. SECOND, THE COMPANY BELIEVES THAT THERE ARE INADEQUATE STANDARDS FOR THEIR MANUFACTURE, INSTALLATION & PERFORMANCE TO ENABLE PG&E TO ASSURE THEIR RELIABILITY. THIRD, PG&E BELIEVES IT IS NOT CLEAR THAT THE CURRENTLY AVAILABLE VALVES WILL NOT CAUSE MORE SAFETY PROBLEMS THAN THEY WILL SOLVE. PG&E HAS FULLY PARTICIPATED IN THE CALIFORNIA UTILITIES PROGRAM TO EVALUATE THE EFFECTIVENESS OF EFV. PG&E HAS ITSELF INSTALLED 52 EFV OF THE NO-BYPASS VARIETY. TO DATE, EFV HAVE OPERATED WITHOUT INCIDENT ON THE PG&E DISTRIBUTION SYSTEM. CONSEQUENTLY, PG&E'S FIELD EXPERIENCE DOES NOT ASSIST IN DETERMINING IF EFV ARE EFFECTIVE IN PREVENTING GAS INCIDENT. THIS PERFORMANCE IS CONSISTENT WITH EFV TEST PERFORMANCE AT OTHER CALIFORNIA GAS UTILITIES. IN THE TESTING GP&E ENCOUNTERED MANY CHARACTERISTIC OF NO-BLEED EFV OPERATION THAT WOULD REQUIRE CHANGES IN THE COMPANY'S SYSTEM DESIGN, OPERATION & MAINTENANCE. PG&E SEES THESE CHANGES AS OBSTACLES THAT COULD OVERCOME SIMILAR TO OBSTACBLES RESULTING FROM OTHER SIGNIFICANT SYSTEM DESIGN CHANGES. HOWEVER, SUCH CHANGES ARE EXPENSIVE TO IMPLEMENT & PG&E BELIEVES THESE COSTS ARE NOT WARRANTED GIVEN THE INCREMENTAL & DEBATABLE INCREASE IN SAFETY DUE TO EFV OPERATION.

Addressee Acronym: PG&E

Addressee Organization Type: P-Private Industry

Communication Date: 1995-08-01

Communication Type: Official Correspondence