The following article might be useful:
http://www.cbi.com/images/uploads/technical_articles/Coker_Design_-_OGJ_-_AUG_-_2009.pdf
Regards CG
http://www.cbi.com/images/uploads/technical_articles/Coker_Design_-_OGJ_-_AUG_-_2009.pdf
Regards CG