# NTSB Safety Recommendation P-81-036 - **operation:** document - **citation:** P-81-036 - **title:** NTSB Safety Recommendation P-81-036 - **source type:** guidance - **agency:** National Transportation Safety Board - **status:** guidance - **official:** true - **published on:** 1981-09-24 - **effective on:** 1981-09-24 - **summary:** AS A RESULT OF SPECIAL STUDY PSS-81-1, THE NTSB RECOMMENDS THAT THE GAS RESEARCH INSTITUTE: DETERMINE THOSE CONDITIONS AND LOCATIONS (OTHER THAN THOSE FOR WHICH THE SAFETY BOARD IS RECOMMENDING IMMEDIATE REGULATORY ACTION--I.E., HIGH PRESSURE, SINGLE-FAMILY RESIDENTIAL SERVICES) FOR WHICH EXCESS FLOW VALVES CAN BE EFFECTIVE IN PREVENTING OR MINIMIZING THE POTENTIAL FOR VARIOUS TYPES OF ACCIDENTS RESULTING FROM LEAKS - **machine formats:** - **json:** https://regulus.evalyn.ai/document/ntsb-recommendation-p-81-036.json - **markdown:** https://regulus.evalyn.ai/document/ntsb-recommendation-p-81-036.md - **app url:** https://regulus.evalyn.ai/document/ntsb-recommendation-p-81-036 - **source url:** https://data.ntsb.gov/carol-main-public/sr-details/P-81-036 **body:** NTSB safety recommendation P-81-036. AS A RESULT OF SPECIAL STUDY PSS-81-1, THE NTSB RECOMMENDS THAT THE GAS RESEARCH INSTITUTE: DETERMINE THOSE CONDITIONS AND LOCATIONS (OTHER THAN THOSE FOR WHICH THE SAFETY BOARD IS RECOMMENDING IMMEDIATE REGULATORY ACTION--I.E., HIGH PRESSURE, SINGLE-FAMILY RESIDENTIAL SERVICES) FOR WHICH EXCESS FLOW VALVES CAN BE EFFECTIVE IN PREVENTING OR MINIMIZING THE POTENTIAL FOR VARIOUS TYPES OF ACCIDENTS RESULTING FROM LEAKS ON HIGH AND LOW PRESSURE SERVICE LINES. AMONG THE CONDITIONS WHICH SHOULD BE EVALUATED ARE GAS DEMAND VARIATIONS, MINIMUM OPERATING PRESSURE, SERVICE LINE SIZE, LENGTH, AND CONFIGURATION, MAJOR LEAKS ON HOUSE PIPING, CLEANLINESS OF GAS, AND EFFECT OF PEAK SHAVING OPERATIONS. Priority: CLASS II Overall Status: Closed - Unacceptable Action Issued Date: 1981-09-24 Adopted Date: 1981-09-09 Overall Date Closed: 1988-09-27 Synopsis: THE NATIONAL TRANSPORTATION SAFETY BOARD HAS CONDUCTED A STUDY OF EXCESS FLOW VALVES DESIGNED FOR USE IN GAS DISTRIBUTION SYSTEMS (SPECIAL STUDY--PIPELINE EXCESS FLOW VALVES, NTSB-PSS-81-1). THESE DEVICES, INTENDED TO STOP THE FLOW OF GAS TO A CUSTOMER IN THE EVENT OF A MAJOR LEAK IN THE GAS SERVICE, HAVE BEEN THE SUBJECT OF CONSIDERABLE CONTROVERSY IN RECENT YEARS. Keywords: Excess Flow Valves Ntsbnumber: 80564 Report Number: PSS-81-01 Addressee Name: Gas Research Institute Addressee Status: Closed - Unacceptable Action Addressee Date Closed: 1988-09-27 Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1981-10-13 Communication Type: Official Correspondence Communication Contents: GAS RESEARCH INSTITUTE (GRI) LTR: THE GAS RESEARCH INSTITUTE HAD PLANNED A RESEARCH PROJECT ON THIS SUBJECT BEGINNING IN 1981, AND WILL INCLUDE THE RESEARCH RECOMMENDED BY THE NTSB AS A PART OF OUR PROJECT TITLED "DEVELOPMENT OF RELIABLE EXCESS FLOW VALVES IN GAS DISTRIBUTION MAINS AND SERVICES." THE PROJECT WILL BEGIN IN 1981 AND WILL REQUIRE ABOUT TEN MONTHS TO COMPLETE AND ISSUE A FINAL REPORT. MR. BARRY SWEEDLER OF THE NTSB, WITH WHOM THE GRI STAFF HAS DISCUSSED THE PROJECT EXTENSIVELY, WILL RECEIVE QUARTERLY PROGRESS REPORTS AS WELL AS THE FINAL REPORT ON THE PROJECT. Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1987-10-26 Communication Type: Official Correspondence Communication Contents: NO RESPONSE--FOLLOWUP LETTER. Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1988-06-29 Communication Type: Official Correspondence Communication Contents: THE RECOMMENDATION WAS ADDRESSED IN A FAULT-TREE ANALYSIS REPORTED ON IN REPORT NO. GRI-86-0022. IN THE RESEARCH BY RISK AND INDUSTRIAL SAFETY CONSULTANTS, INC. A DETAILED FAULT-TREE WAS DEVELOPED TO IDENTIFY INSTANCES WHERE THE PRESENCE OF AN EFV WOULD HELP IN REDUCING THE SEVERITY OF INCIDENTS. THE FAULT-TREE WAS STRUCTURED USING DESCRIPTIONS OF INCIDENTS BY INDUSTRY PEOPLE AS WELL AS DOT INCIDENT REPORTS AND RELEVANT NTSB ACCIDENT REPORTS. THE ANALYSIS WAS QUANTIFIED WITH THE USE OF DATA FROM THE PREVIOUS GRI REPORT EVALUATING EXCESS FLOW VALVES, HISTORICAL DATA AND ENGINEERING JUDGMENT TO ARRIVE AT THE REDUCTION IN RISK (BENEFIT) THAT MAY BE ATTRIBUTED TO EFVS. THE REPORTED RESULTS IN GENERAL USE "AVERAGE INDUSTRY COSTS AND BENEFITS." HOWEVER, A SENSITIVITY ANALYSIS HAS ALSO BEEN PERFORMED TO EXAMINE THE SENSITIVITY OF RESULTS TO SOME UNCERTAIN PARAMETERS. ALSO, A COMPUTER PROGRAM HAS BEEN DEVELOPED AND DISTRIBUTED TO EVALUATE THE COSTS AND BENEFITS AND, IF DESIRED, THE COST/BENEFIT RATIO FOR EFV UTILIZATION ON INDIVIDUAL GAS DISTRIBUTION SYSTEMS OR IN SPECIFIC SITUATIONS THAT MAY BE OF INTEREST TO THE USER. AS STATED IN NTSB CHAIRMAN BURNETT'S OCTOBER 26, 1987 LETTER TO GRI AND CONFIRMED BY THE NTSB STAFF AT THE MARCH 21, 1988 MEETING ONLY REPORT NO. GRI- 85/0150 WAS CONSIDERED BY NTSB IN THE INITIAL EVALUATION OF GRI'S RESPONSE TO THE NTSB RECOMMENDATION. IT IS REQUESTED THAT THE NTSB CLASSIFICATION OF GRI'S RESPONSE BE RECONSIDERED AND BASED ON THE RESEARCH REPORTED ON IN REPORT NO. GRI-86-0022. Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1987-10-26 Communication Type: Official Correspondence Communication Contents: AFTER MUCH STUDY OF THE GAS RESEARCH INSTITUTE (GRI) REPORTS AND MANY DISCUSSIONS BETWEEN GRI AND THE SAFETY BOARD MANAGEMENT DURING DEVELOPMENTS OF THE REPORTS, THE SAFETY BOARD TOLD THE GRI THAT THE BOARD HAD REJECTED THE GRI REPORTS AS BIASED. THE BOARD SAID P-81-35 AND -36 WERE CLASSIFIED "CLOSED--UNACCEPTABLE ACTION." IN THE GRI'S 11/13/87 RESPONSE, THE PRESIDENT (OF GRI) SUGGESTED THAT THE BOARD HAD NOT BEEN FAIR WHEN IT CLASSIFIED THE SAFETY RECOMMENDATIONS AND THAT THE SAFETY BOARD AND THE GRI HAVE A MEETING. Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1988-09-27 Communication Type: Official Correspondence Communication Contents: ON 3/21/88, GRI MANAGEMENT MET WITH SAFETY BOARD MANAGEMENT TO DISCUSS THE SAFETY BOARD'S CONCERNS ABOUT THE GRI'S LACK OF OBJECTIVITY AND ACCURACY. ALTHOUGH GRI MANAGEMENT ACKNOWLEDGED THE MERITS OF MANY SAFETY BOARD CONCERNS, IT STATED THAT FURTHER WORK TO CORRECT DEFICIENCIES WOULD NOT BE PERFORMED BECAUSE THE GRI HAD ALREADY DEVOTED TOO MUCH TIME AND MONEY TO THE PROJECT. AFTER RECONSIDERING THE GRI'S WORK, ON 9/27/88, THE SAFETY BOARD CHAIRMAN ADVISED THE GRI THAT THE BOARD HAD CONCLUDED THAT THE GRI HAD NOT MET THE OBJECTIVE OF P-81-36 AND THAT THE REPORT WAS BIASED AND NOT AT ALL OBJECTIVE REGARDING EFV'S COULD BE USED TO IMPROVE PUBLIC SAFETY AND PREVENT DEATH, INJURY, AND PROPERTY DAMAGE. THE STATUS OF P-81-36 REMAINED "CLOSED--UNACCEPTABLE ACTION." (THE STATUS OF P-81-35 WAS ALSO NOT CHANGED AS A RESULT OF THE MEETING AND REMAINED CLASSIFIED "CLOSED--UNACCEPTABLE ACTION.) Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1987-11-13 Communication Type: Official Correspondence Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1988-10-27 Communication Type: Official Correspondence Addressee Acronym: GRI Addressee Organization Type: A-Associations Communication Date: 1981-12-16 Communication Type: Official Correspondence - **truncated:** false - **body characters:** 6310