FOREWORD This specification was prepared by a formulating committee on which were representatives of the American Petroleum Institute@ the American Gas Association@ the Pipe Line contractors Association@ the American Welding Society@ the Society for Non-destructive Testing@ and representatives of the pipe manufacturers and individuals associated with related industries. In is the purpose of this specification to produce the highest quality welds obtainable on a commercial basis by skilled welders@ using approved welding procedures@ materials@ and equipment. It is also the purpose of this specification to produce the highest quality radiographs obtainable by skilled operators@ using approved technique and equipment@ to ensure the proper analysis of welding quality and defects. This specification is intended to apply to cross country pipe lines for the transmission of crude petroleum@ petroleum products@ and natural gas. The committee has had the cooperation of many engineers interested in design@ construction@ and operation of oil and gas pipe lines@ and desires to express appreciation for their wholehearted and valuable assistance. It is realized that revisions will be necessary from time to time to keep abreast of developments@ and constructive suggestions will be welcome. Publication of teh specification presented herein has been authorized by the American Petroleum Institute and the American Gas Association.