Edition 2004 of 31.3 has appendix P, which I feel lists alternative rules . These are not replacing the rules in Chapter II of 31.3.
Please comment in case I am not right.
Regards,
Sunil

As far I have understood Appendix-P is an extension of Chap-I and II or an illustration of those chapters. However, since it is specifically meant for piping flexibility analysis so it overrides some of the rules stated in Chap-I and II for specific cases.

Dear Arijit,
Thanks for yr reply.Could you be more specific?
Regards,
Sunil

Paragraph P300(c) states "In the application of these alternative rules, all of the provisions of Chapters I and II of the base Code apply, except those that are specifically modified by this Appendix."

I reviewed this change in the December 2004 Mechanical Engineering News. That article is available on our web site.

To make sure it is perfectly clear, I offer the following.

Is is an ALTERNATIVE.

You may use the prior rules that are in Chapter II, or you may use Appendix P for flexibility analysis.