NTSB Safety Recommendation Letter P-74-016 through P-74-027

Page 1Official PDF- 22 - tion, which applied a bending force to the pipe i n an area weakened by I graphitization. Contributing to the explosion were the f a i l u r e of the gas company to shut off the flow of gas to the leak s i t e and the inadequate efforts of i the gas-company personnel t o prevent the ignition of the leaking gas I detected i n the building. ! i EECOMI.IENDATIONS i The National Transportation Safety Board recommends that: 1. i The Office of Pipeline Safety of the Department of Transporta- ~ tion: ! (a) Revise49CFR 192.741torequire pipeline operators t o t e l e - meter gas pressure or flow data i n such a way as t o insure ! prompt warnings of significant system failures shown by pressure or flow changes. The type and location of the data points should be considered on an individual basis and should include single-fed systems serving substantial numbers of customers. (Recomendation No. P-74-16) (b) Define what constitutes an emergency and provide clarifica- tion of the requirements of emergency procedures under 49 CFR 192.615, Emergency plans. (Recomendation No. P-74- 17) I ! (c) Require that designated emergency valves be the valves ~ closed i n i t i a l l y when a section of main i s required t o be isolated i n an emergency. (Recornendation No. P-74-18) 2 . The American Society of Mechanical Engineers Gas Piping Standards C o d t tee : (a) Develop guidelines for the use of telemetering on gas dis- tribution systems so that system failures can be promptly detected. (Recormendation No. P-74-19) (b) Expand the guidelines on the prevention of accidental ig- nition, to provide for more comprehensive guidance to pipe- l i n e operators when gas i s detected i n buildings and struc- tures. The guidelines should include such subjects as ventilation of structures, prohibition of electrical switch operation, and occupant evacuation. This work should be coordinated with the guidelines currently being developed#

Page 2- 2 7 - concerning the actton to be taken by the first gas company employee arriving at the scene of an emergency. 11 (Recommendation No. P - 7 4 - 2 0 ) 3 . The Missouri F'ublic Service Company: Expand its emergency procedures to include the actions to be taken in all types of emergencies. (Recommendation No. P - 7 4 - 2 1) Install telemetering equipment at the Clinton and other town border stations, so that system failures can be promptly de- tected. (Recommendation No. P - 7 4 - 2 2 ) Expand its formal training program to provide employees who respond to reported leaks with the knowledge and techniques required to assist them in handling emergency situations. (Recommendation P - 7 4 - 2 3 ) Takeremedial action to reduce the possibility of breakage of cast-iron mains. This actionshould includereplacement of those sections of cast-iron main susceptible to failure. (Recom- mendation P - 7 4 - 2 4 ) Develop a sectionalizing program of its high-pressure distri- bution system so that preplanned procedures are available to isolate any section of its system in an emergency. (Recom- mendation No. P - 7 4 - 2 5 ) Train and equip all appropriate radio-equipped field personnel (including electric servicemen) to locate and operate main line valves in emergencies. (Recommendation No. P - 7 4 - 2 6 ) Provide valve location and other necessary information to dispatchers in radio contact with servicemen, supervisors, and repair crews, so that emergency efforts can be expedi- tiously coordinated. (Recommendation No. P - 7 4 - 2 7 ) - 81 See NTSB Recommendation P - 7 2 - 4 8 contained in N T S B - P I W - 7 2 - 4 .#