Gas del Estado — Pipeline Safety Interpretation

Page 1Mr. Jose Hugo Muraco Jefe de Normalizacian Tecnica Gas del Estado Centro Communicaciones Don Bosco Buenos Aires, Argentina Dear Mr. Muraco: This responds to your telefax #536 dated October 21, 1991, in the order of your specific questions as stated in your telefax: 1. 2. 3. Question: §192.1(b) What is the limit between gathering and other facilities? Likewise, what regulations, standard or code do you suggest for the design of gathering lines or networks to comply with? Answer: With regard to your question on the limit between gathering and other facilities, I am enclosing a Notice of Proposed Rulemaking (56 FR 48505; September 25, 1991) proposing a more precise definition for gathering lines, including a clearer delineation of the end point of a gathering line. The final rule on this proposed definition will be issued in 1992. In accordance with §192.9, each gathering line must comply with the requirements of Part 192 applicable to transmission lines. Question: §192.111(b) In paragraph (4) river crossing headers are specifically mentioned within the examples of fabricated assembly to be calculated with design factor 0,6 for Class 1 location. Nowhere in this sub-section (b) is the river crossing itself mentioned; thus, should it be interpreted that for this latter it is not required a "reinforced" calculation by applying such factor? Answer: In accordance with §192.111(d), a design factor of 0.50 or less must be used in the design formula in §192.105 for Class 1 and Class 2 locations for steel pipe located in inland navigable waters, such as rivers. Question: §192.245(a) Why welds to be repaired on a pipeline vessel are exempted from the requisite of being removed if the crack exceeds 8% of the weld length, considering that the acceptance conditions for such lengths of pipeline should be more restrictive and the line is still being installed (not fully descended from the vessel)? Then, for this specific case, what type of repair do you recommend? Besides, the 8 percent mentioned should be DB C:\WP51\INTERPRT\192\1\92-01-07 1#

Page 2interpreted as corresponding to a single crack, or more than one crack are admissible with such 8% as sum for their lengths? Answer: You inquire why welds to be repaired on an offshore pipeline being installed from a pipeline vessel are exempted from the requirements of being removed if the crack exceeds 8% of the weld. This exception for offshore pipelines was provided because of the difficulties in removing or repairing welds on a pipeline vessel. The repair of a crack must be done in accordance with §192.245(b) and (c). You further inquire if the crack that is more than 8 percent of the weld length that must be removed pursuant to §192.245(a) is a single crack or more than one crack. The limitations on this requirement applies to one crack or more than one crack that cumulatively may exceed 8 percent of the weld length. I trust that this adequately responds to your questions. Sincerely, /signed/ Cesar DeLeon Director Regulatory Programs Office of Pipeline Safety DB C:\WP51\INTERPRT\192\1\92-01-07 2#