NTSB Safety Recommendation Letter P-91-011

Page 1Official PDFNational Transportation Safety Board Washington, D.C. 20594 Safety Recommendation Date: .July 17, 1991 In reply refer t o : P-91-11 Mr. Michael Baly, 111 President American Gas Association 1515 Wilson Boulevard Arlington, Virginia 22209 Mr. Charles J. DiBona President American Petroleum Institute 1220 L Street, N.W. Washington, D.C. 20037 Mr. Jerome J. McGrath President Interstate Natural Gas Association of America 1660 L Street, N.W. Washington, D . C . 20036 On March 13, 1990, the Texas Eastern Products Pipeline Company (TEPPCO) line P-41, an 8-inch-diameter liquid propane pipeline, ruptured within a pipeline casing beneath County Road 43 (CR 43) near the Village of North Blenheim, New York. Liquid propane gas escaped from the ends of the casing, vaporized, and formed a white, heavier-than-air gas cloud. The gas cloud flowed downhill along CR 43 until it entered North Blenheim and ignited. The fire quickly consumed the propane vapor and flashed back to the pipeline rupture. Two people were killed, seven persons injured, and more than $4 million in property damage and other costs resulted.' The TEPPCO repair program did not incorporate several essential industry-recommended practices that: repairs be covered in the maintenance plan, they be performed under qualified supervision, they be performed by trained personnel, and all employees be briefed on the procedures to be followed for accomplishing the repairs. In deciding to implement a special program to correct longstanding deficiencies, the TEPPCO's management should have recognized that this program was different from routine maintenance work because the TEPPCO had not previously assigned such work to its employees. The TEPPCO then should have evaluated its procedures, supervision requirements, and the experience and training of its maintenance employees in light of the industry recommended practices. 'For more detailed information, read Pipeline Accident Report--"Propane Pipeline Rupture and Fire, Texas Eastern Products Pipeline Company, North Blenheim, Neu York, March 13, 1 9 9 0 " (NTSE/PAR-Ql/Ol). 53 1 PA#

Page 22 Had t h e TEPPCO recognized t h a t the casing r e p a i r program was d i f f e r e n t from r o u t i n e maintenance and evaluated t h e procedures, maintenance personnel would have been b e t t e r d i r e c t e d and guided t o c o r r e c t l y perform t h e required work. A review of t h e experience and t r a i n i n g o f employees revealed t h a t many had not been t r a i n e d on applicable procedures o r d i d not possess t h e work experience needed f o r moving pressurized p i p e f o r the purpose o f e l i m i n a t i n g casing e l e c t r i c a l shorts. These d e f i c i e n c i e s should have been recognized by t h e TEPPCO’s management and corrected before t h e program was implemented. A t a minimum, t h e TEPPCO management should r e q u i r e t h a t work be c l o s e l y supervised by a person knowledgeable o f t h e procedures and the methods t o successfully perform the work. Also, employees should be b r i e f e d on t h e procedures they are t o perform. The TEPPCO procedure No. 70 on r e p a i r s t o p i p e l i n e s included the Federal requirement f o r lowering t h e pressure i n t h e l i n e section t o be moved, and i n addition, i t required t h a t the l i n e section be i s o l a t e d before movement. However, i t d i d not include the Federal requirement f o r p r o t e c t i n g t h e p u b l i c , by adequate warning t o evacuate, from t h e hazards o f moving h i g h l y v o l a t i l e l i q u i d (HVL) pipelines. A d d i t i o n a l l y , n e i t h e r t h i s procedure nor t h e Federal regulations contain guidance o r c r i t e r i a on t h e extent t h a t a pipe o f s p e c i f i c strength, grade, diameter, and w a l l thickness t h a t contains hazardous products may be s a f e l y moved, nor do t h e procedure and regulations r e q u i r e t h a t t h i s information t o be calculated before movement. Although t h e pipe d i d not f a i l during i t s movement, a d d i t i o n a l e l e v a t i o n by j a c k i n g probably would have caused a f a i l u r e . Fortunately, t h e TEPPCO supervisor a t t a i n e d t h e clearance he needed between the pipe and i t s casing before t h e pipe f a i l e d . This was a f o r t u i t o u s event r a t h e r than t h e r e s u l t o f a prudent judgment. This accident shows t h a t t h e stress l i m i t s can be e a s i l y exceeded during r e p a i r s . It underscores t h e need f o r operators t o make s i t e s p e c i f i c stress c a l c u l a t i o n s r e l a t i v e t o t h e pipe t o determine how t o move it safely. Because o f the low f r a c t u r e toughness o f most pipe s t e e l , pipes are most susceptible t o f a i l u r e a t low ambient temperatures. Therefore, p i p e l i n e operators should determine before pipe movement, e s p e c i a l l y on HVL pipelines, the amount o f pipe t o be uncovered, t h e proper s i t e f o r f o r c e application, and t h e maximum movement a pipe can s a f e l y withstand. Therefore, t h e National Transportation Safety Board recommends t h a t the American Gas Association, t h e American Petroleum I n s t i t u t e , and t h e I n t e r s t a t e Natural Gas Association o f America: N o t i f y your members o f the circumstances o f t h i s accident and urge them t o develop e x p l i c i t procedures on t h e support, movement, and other handling o f pressurized p i p e l i n e s and t o develop t r a i n i n g and t e s t i n g programs t o annually q u a l i f y employees t o perform each r e s p o n s i b i l i t y assigned t o them. (Class 11, P r i o r i t y Action) (P-91-11)#

Page 33 Also, the Safety Board issued Safety Recommendations P-91-1 through -4 and reiterated P-84-26 and P-87-2 and -22 to the Research and Special Programs Administration of the U.S. Department of Transportation and issued P-91-5 through -10 to the Texas Eastern Products Pipeline Company. The National Transportation Safety Board is an independent Federal agency with the statutory responsibility "to promote transportation safety by conducting independent accident investigations and by formulating safety improvement recommendations" (Public Law 93-633)" The Safety Board i s vitally interested in any action taken as a result o f its safety recommendations. Therefore, it would appreciate a response from you regarding action taken or contemplated with respect to the recommendation in this letter. Please refer to Safety Recommendation M-91-11 in your reply. KOLSTAD, Chairman, COUGHLIN, Vice Chairman, LAUBER, BURNETT, and HART, Members, concurred in this recommendation. Chairman#