I felt it would be useful to the reader to summarize changes, in particular for those that may have spent the time to already read through the 2004 edition of this book. This is not a complete summary of changes, but provides most of the major changes. The major additions relate to new Code requirements included in the 2006 and 2008 editions of ASME B31.3. These include the following. 1. New requirements for weld joint strength reduction factors, in Section 3.4. 2. Changes to Section VIII references to be consistent with the rewritten Code, in Section 4.15, 9.3, Insert 9.2 and 17.6. 3. Addition of requirement for valve stem retention, in Section 5.2. 4. Update on various standards, in Chapter 5. 5. Discussion of Code Case 178, which provides a specifi c equation for evaluation of longitudinal stresses due to sustained loads, in 6.2. 6. New requirements for design of supports, in Section 9.3. 7. Replacement for Table 12.2 with the revised version from the 2006 edition. 8. Discussion of Code text added to clarify the intent of some progressive examination requirements, in Section 13.2. 9. Addition of Code Case 181 to provide acceptance criteria for advanced ultrasonic techniques that size defects, in Section 13.3. 10. Additional requirements and discussion of subassemblies that have been previously tested, in Section 14.1. 11. Revised hydrostatic test requirements, in Section 14.2. 12. Addition of a Code Case for testing jacketed piping, in Section 14.7. 13. Changes to the pressure design equations for high pressure piping, in Section 17.3. 14. Coverage of use of listed materials to other editions, in Section 17.7. 15. Addition of leak test alternatives for high pressure piping, in Section 17.10. In addition, a few additional topics were covered. These include the following. 1. Addition of the photo taken at the 125th meeting of the ASME B31.3 Section Committee. 2. Addition of new Task Group H in the committee, in Section 1.6. 3. Additional discussion of requirements for Listed Components, in Section 2.3. 4. Mention of Appendix L, in Section 4.11. 5. Discussion of ASME Research on stress limits for occasional loads at elevated temperatures, in Section 6.3. x What's New in the 2008 Edition of This Book? 6. Mention of new considerations with respect to fatigue design rules, in Section 7.1. 7. Mention of examples added to Appendix S in the 2006 edition, in Section 8.1. 8. Discussion of branch connection attachment welds, in Section 12.12. 9. Reference to procedures to calculate stored energy and safe distances for pneumatic tests, in Section 14.3. 10. Component pressure-temperature ratings in Appendix I were updated in accordance with changes in the subject standards.