This third edition of the Companion Guide of ASME Boiler & Pressure Vessel and Piping Codes has been updated to the current (2007) Code Edition. Since the first edition, a total of 140 authors have contributed to this publication, and in this edition there are 107 contributors of which 51 are new authors. Several of the new contributors are from countries around the world that use ASME B&PV Codes, with knowledge of ASME Codes, in addition to expertise of their own countries' B&PV Codes. All of these authors who contributed to this third edition considerably updated, revised or added to the content matter covered in the second edition to address current and future trends as well as dramatic changes in the industry. The first two volumes covering Code Sections I through XI address organizational changes of B&PV Code Committees and Special topics relating to the application of the Code. Volume 1 covers ASME Code Sections I through VII, B31.1 and B31.3 Piping Codes. Volume 2 has chapters addressing Code Sections VIII through XI, refurbished with additional code material consistent with the current 2007 Code edition. ASME Code Section VIII Division 2 was completely rewritten, and that effort has been captured in this publication. Notable updates included in this Volume relate to maintenance rule, accreditation, dynamic loads, functionality, operability criteria, fluids, pipe vibration analysis, code design and evaluation for cyclic loading for Code Sections III and VIII.