PLIDCO — Pipeline Safety Interpretation

Page 1Mr. W. C. Zanders Chief Engineer PLIDCO 870 Canterbury Road Cleveland, OH 44145-1419 Dear Mr. Zanders: By letters of May 21 and October 22, 1990, addressed to Richard Beam, you asked about the installation of a "full encirclement welded split sleeve" under 49 CFR 192,713(a)(2) and 192.715(c). Please accept my apology for the unusual delay in replying to your letters. First, you asked whether the sleeve ends and pipe must be joined by circumferential fillet welds. Section 192.713(a) governs the repair of certain pipe imperfections or damage discovered in transmission lines operating above 40 percent of SMYS, and §192.715 governs the repair of certain girth weld defects discovered in any transmission line in service. Although both rules require the installation of a full encirclement welded split sleeve for certain repair situations, the rules are silent on whether the installation must include circumferential fillet welds. Such welds are required, therefore, only when necessary to accomplish the purpose of the installation. If the imperfection or damage or girth weld defect is not leaking and may not reasonably be expected to leak, the purpose of installing a full encirclement welded split sleeve is to bolster the strength of the pipeline in the vicinity of the imperfection or damage or girth weld defect. This purpose can be accomplished without welding the sleeve ends to the pipe; so circumferential fillet welds are not required. However, if the imperfection or damage or girth weld defect is leaking or may reasonably be expected to leak, the purpose of the full encirclement welded split sleeve is not only to bolster the strength of the pipeline, but also to stop the present or possible future leak. In this case, either circumferential fillet welds or other suitable means must be used to permanently seal the sleeve ends and contain the pipeline pressure. Circumferential fillet welds would be required only if the other means available would not accomplish that purpose. Next you asked if the two half shells that form the full encirclement welded split sleeve must be joined by welding or may they be joined mechanically. Under §§192.713(a)(2) and 192.715(c), in the phrase "full encirclement welded split sleeve," the term "welded" modifies the term "split sleeve." The meaning of the combined terms is that the two half shells must be joined by welding. In contrast, §192.713(b) expressly allows submerged pipelines to be repaired by mechanically joining the two half shells of a full encirclement split sleeve. Note that in §192.713(b) the term "welded" does not appear in the phrase "full encirclement split sleeve." DB C:\WP51\INTERPRT\192\713\91-03-21 1#

Page 2Please let me know if we can be of any further assistance in understanding the Part 192 regulations. Sincerely, /signed/ George W. Tenley, Jr. Associate Administrator for Pipeline Safety DB C:\WP51\INTERPRT\192\713\91-03-21 2#