The inviscid-diabatic (Rayleigh) and the viscous-adiabatic (Fanno) one-dimensional flows of real steam are studied using the accurate state equation of H2O proposed by Saul-Wagner in comparison to that of Redlich-Kwong. The accurate results describing the Fanno and Rayleigh curves are approximated by explicit empirical relations which have mathematical forms similar to the ideal gas equations of the Rayleigh and Fanno curves, but with new coefficients and exponents numerically calculated [1-4]. (see (1) Kouremenos, D. A; and Kakatsios, X. K., Forschung im Ingenieuresen, 1985, 51, 169-174; (2) Kouremenos, D. A. and Kakatsios, X. K., BWK 37, 1985, 263-265; (3) Kakatsios, X. K., Acta Mechanica, 1995, 110, 185-197; (4) Kakatsios, X. K. and Houzouris, G. E., Archive of Applied Mechanics, 1995, 65, 217-226.)