The purpose of this Specification is to provide standards for pipe suitable for use in conveying gas@ water@ and oil in both the oil and natural gas industries. This Specification covers welded steel continuously milled coiled line pipe in the size range 0.5 in. (12.7 mm) to 6.625 in. (168.3 mm). Pipe that is pipe-to-pipe welded outside the confines of the manufacturing plant is not included within this document. Grades covered by this specification are X52C@ X56C@ X60C@ X65C@ X70C@ X80C@ and X90C. Grades shall not be mixed within a milled length@ or a spool. Note: Grade designations used herein are composed of the letter X followed by the first two digits of the specified minimum yield strength in U.S. customary units@ and the letter C is added to indicate coiled pipe. Pipe manufactured as Grade X60C or higher shall not be substituted for pipe ordered for Grade X52C without purchaser approval. Although the coiled line pipe meeting this specification is intended to be suitable for field welding@ the manufacturer will not assume responsibility for field welding. The size designations used herein are outside-diameter sizes. Pipe sizes 2-3/8 and larger are expressed as integers and fractions; pipe sizes smaller than 2-3/8 are expressed to three decimal places. US customary units are used in this specification; SI (metric) units are shown in parentheses in the text and in many tables. See Appendix M for specific information about conversion factors and rounding procedures. The suitability of these products for use in environments containing hydrogen sulphide is outside of the scope of this document.?