9 Subsection NE—Class MC Components

This chapter provides a summary of some of the significant requirements of the ASME Code Section III, Subsection NE Class MC vessels, and a commentary on these requirements. It begins with an overview of the scope of Subsection NE and the boundaries of its jurisdiction. The chapter then outlines the general material requirements for Class MC vessels that are specified in Article NE-2000. This is followed by a discussion on material toughness requirements and design and analysis requirements. The chapter provides information on Certified Material Test Reports and on certifications that must be performed by engineers who prepare design and overpressure protection reports. The chapter then describes the rules for the following analyses of containment vessels as defined in Subsection NE: fatigue analysis, buckling analysis, design by analysis, and plastic analysis. An outline of the rules for reinforcement of cone-to-cylinder junctions, overpressure protection, bolted flange connections, and welded connections, is also presented. The closing pages cover the following topics: tolerance requirements for some commonly used shells; fabrication requirements for each weld category as specified in NE-4240; welding procedure qualification; rules for marking, examining, and repairing welds; and nondestructive testing personnel qualification and certification. A number of Code Cases and references regarding the rules of Subsection NE are cited, with cross-references to other Code Sections and Subsections.