9.0. Introduction
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Published:1996
The American Petroleum Institute has published and updated specifications for the manufacturing of line pipe since 1928. The first such specification, API Standard No. 5-L, First Edition, was issued in January, 1928. The First Edition was a “pocket-sized” (4 × 7 inches) 38 page document. The most recent edition: API Specification 5L, Forty-First Edition, is dated April 1, 1995. It is an 8½- by 11-inch book of 119 pages. Along the ~ay the document has undergone many changes but the essential purpose has remained the same, namely, “to provide standards for pipe suitable for use in conveying, gas, water, and oil in both the oil and natural gas industries”. The elements of pipe manufacturing addressed by the standard have remained essentially the same, namely, processes of manufacturing, material properties, dimensional requirements, workmanship, inspection, testing, threading and couplings, and marking and documentation. Nevertheless, if one were to compare the First Edition to the Forty-First Edition, one would notice significant modifications mostly in response to both increasing emphasis on product quality and improvements in manufacturing technology. Summaries of the requirements of each API 5L edition are listed in Table 9-1, and summaries for API 5LX editions are listed in Table 9-2. Listings of which manufacturers held 5L and 5LX licenses and when they held them are presented in Tables 9-3, 9-4, and 9-5. The contents of the various editions are described below.