IAPWS-IF97 formulation - http://www.iapws.org/relguide/IF97-Rev.pdf
If you do a reference on the link http://twt.mpei.ac.ru/TTHB/NPP/mathcad-functions/H2O.xmcdz in your work-sheet.
You can find in attach some same functions for Mathcad Prime too.
Some functions with properties of water and steam will be visible in the sheet as it is showed on this picture:
Image may be NSFW.
Clik here to view.
Prof. Valery Ochkov - a member of the Working Group of The International Association for the Properties of Water and Steam
Clik here to view.
