scope:

Foreword

a. This specification is under the jurisdiction of the Committee on Standarization of Tubular Goods of the American Petroleum Institute, and was prepared with the cooperation of the American Gas Association.

b. 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.

c. For regular-weight and special plain-end pipe, and standard-weight threaded pipe larger than 12-in. nominal, the size designations used herein are outside-diameter sizes. For all other pipe, the size designations are nominal sizes. In the text paragraphs herein, where pipe size limits (or size ranges) are given, these are outside-diameter sizes except where stated to be nominal. These Outside-diameter size limits and ranges apply also to the corresponding nominal sizes.

d. Class II steel is rephosphorized and probably has better threading properties than class I. Because class II pipe has higher chemical properties than class I, it may be somewhat more difficult to bend.

e. Metric units in this specification are shown in italic type and in the text and most tables in parentheses. Outside diameters and wall thicknesses are converted from inch dimensions. The converted values are rounded to the nearest 0.1 mm for diameters less than 18 in. and to the nearest 1.0 mm for diameters 18 in. and larger. Wall thicknesses are rounded to the nearest 0.1 mm.

Metric inside diameters and drift diameters are calculated from the metric diameters and wall thicknesses and rounded to the nearest 0.1 mm.

Metric hydrostatic test pressures are calculated from the metric outside diameters and wall thicknesses and metric fiber stresses.