The Companion Guide to the ASME Boiler & Pressure Vessel Code: Criteria and Commentary on Select Aspects of the ASME Boiler, Pressure Vessel and Piping Codes is available from ASME International (American Society of Mechanical Engineers). The book is a two-volume, 1,400-page guide that enables users to understand the basic rationale of the code as deliberated and disseminated by ASME.