Vinay,

Sec VIII DIV 1 APPENDIX 2 , APPENDIX S AND APPENDIX Y are not the only sources for doing a flange analysis. SEC VIII DIV 2 , SEC III and B31.8 also has methods. For a comprehensive view of the different applicable methods see Compansion Guide to ASME Boiler and PV Code ( edited by K.R.Rao) chpter on Flange analysis.There are other standards also like say EN1591 but it is too involved.

Regards