1.1 This specification covers five grades of electric-fusion (arc)-welded straight-seam or helical-seam steel pipe. Pipe of NPS 4 (Note 1) and larger with nominal (average) wall thickness of 1.0 in. [25.4 mm] and less are covered. Listing of standardized dimensions are for reference (Note 2). The grades of steel are pipe mill grades having mechanical properties which differ from standard plate grades. The pipe is intended for conveying liquid, gas, or vapor.

Note 1—The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as “nominal diameter,”“ size,” and “nominal size.”

Note 2—A comprehensive listing of standardized pipe dimensions is contained in ASME B36.10M.

Note 3—The suitability of pipe for various purposes is somewhat dependent on its dimensions, properties, and conditions of service. For example, for high-temperature service see applicable codes and Specification A691.

1.2 The values stated in either inch-pound units or in SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values in each system are not exact equivalents; therefore, each system is to be used independently of the other.

ASTM Standards

A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A691 Specification for Carbon and Alloy Steel Pipe, Electric-Fusion-Welded for High-Pressure Service at High Temperatures
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
E59 Practice for Sampling Steel and Iron for Determination of Chemical Composition (withdrawn)

American Welding Society Standard

AWSB2.1 Standard for Welding Procedure and Performance Qualifications Welding Handbook, Vol 1, 8th ed

ASME Standards

ASME Boile rand Pressure Welding Qualifications