NTSB Safety Recommendation Letter P-73-047 through P-73-054

Page 1Official PDF/ - 2 1 - Contributing t o the amount of NGL released were (1) the long d i s - tance between remotely controlled main-line valves and (2) t h e v o l a t i l - i t y of NGL, which permitted the escape of most of the NGL i n t h e i s o l a t e d s e c t i o n of pipeline. VI. REC0M"DATIONS The National Transportation Safety Board recommends t h a t : 1. The O f f i c e of P i p e l i n e Safety of t h e Department of Transporta- tion: (a) Expedite rulemaking c u r r e n t l y under study t o provide f o r more complete and e f f e c t i v e c o n t r o l s over the t r a n s p o r t a t i o n by p i p e l i n e of l i q u e f i e d petroleum gases, which would include n a t u r a l gas l i q u i d s . These r e g u l a t i o n s should contain minimum standards f o r t h e design, con- s t r u c t i o n , t e s t i n g , operation, and maintenance of both new and e x i s t i n g p i p e l i n e s . (Recornendation No. P-73-47) (b) Undertake rulemaking concerning methods of handling, contain- i n g , and disposing of l i q u e f i e d petroleum gases involved i n p i p e l i n e f a i l u r e s . This rulemaking should take i n t o account such e x t e r n a l f a c t o r s as weather conditions, leak s i t e topography, and population d e n s i t y . (Recomendation No. P-73-48) (c) Amend 49 CFR 195 t o e s t a b l i s h an educational program to enable customers and t h e general public t o recognize and r e p o r t l i q u e f i e d petro- leum gas leaks t o appropriate o f f i c i a l s . These regulations should be similar t o those which appear i n 49 CFR 192, "Transportation of Natural and Other Gas by Pipeline; Ninimum Safety Standards." (Recommendation NO. P-73-49) (d) IJndertake a study of the e f f e c t s of pipe stress concentration caused by improper weld positioning and improper welding techniques. Based on the r e s u l t s of t h i s study, incorporated i n t o 49 CFR 195 speci- f i c a t i o n s f o r p i p e l i n e repair-welding procedures designed t o avoid stress concentrations. (Recommendation No. P-73-50) 2. The P h i l l i p s Pipe Line Company: (a) Examine i t s p i p e l i n e system and excavate the l i n e on a random- sample b a s i s i n areas where full-wrap reinforcement sleeves have been i n s t a l l e d , and inspect those repaired s e c t i o n s for possible a r e a s of stress concentration. (Recommendation No. P-73-51) (b) Amend its Maintenance Operating EIanual t o include a s e c t i o n on stress concentration as a r e s u l t of improper r e p a i r welding. (Recom--\endation No. P-73-52)#

Page 2- 22 - (c) I n s t r u c t i t s p i p e l i n e maintenance crews on t h e importance and n e c e s s i t y of proper positioning of welded reinforcement sleeves to mini- mize t h e chance of stress concentration on t h e c a r r i e r pipe. (Recomenda- t i o n No. P-73-53) (d) Nake comprehensive s o i l tests along t h i s e n t i r e p i p e l i n e r i g h t - of-way p a r t i c u l a r l y i n a r e a s where p i p e l i n e f a i l u r e s have occurred. A s a r e s u l t of these tests, P h i l l i p s should check the pipe i n a r e a s of severe s o i l swell p o t e n t i a l and should replace, anchor, or provide addi- t i o n a l slack f o r pipe through t h e area. (Recornendation No. P-73-54) BY THE NATIONAL TRANSPORTATION SAFETY BOARD: / S / JOHN H. REED -1 Chairman / s / FRANCIS-H. McADAMS __ Member / s f LOUIS M. THAYER Member / s / ISABFL A. BURGESS Member / s / IJILLIAM R. HALEY Member November 7 . 1973#