t1 is set equal to ts!

For vaporous media, the program always checks whether the temperature of the medium at the valve inlet is at least as great as the saturated steam temperature. If it is determined that it is too small, i.e. that a 2-phase mixture rather than pure steam is present, t1 is set equal to the saturated steam temperature.

Note: The calculation of 2-phase mixtures is not possible with this version of the program.