This second edition expands the scope of the 1980 version, updating original text to incorporate a revised theory of design, new materials and more “user friendly” tables. Included are new tables for stainless steels and aluminum, plus expanded chapters on materials, welding practices, and a guide specification. It covers the simple, low or moderate temperature and pressure (or vacuum) indoor systems as well as the more complex outdoor systems that operate at moderate to high temperature and pressure (or vacuum), and are subject to higher and more complex external loading. Approved as an American National Standard (ANSI/SMACNA 002-2011).