@classmethod
def _Vapor_Enthalpy(cls, T):
    """Auxiliary equation for the specific enthalpy for saturated vapor

        Parameters
        ----------
        T : float
            Temperature, [K]

        Returns
        -------
        h : float
            Saturated vapor enthalpy, [kJ/kg]

        References
        ----------
        IAPWS, Revised Supplementary Release on Saturation Properties of
        Ordinary Water Substance September 1992,
        http://www.iapws.org/relguide/Supp-sat.html, Eq.7
        """
    alfa = cls._alfa_sat(T)
    rho = cls._Vapor_Density(T)
    dpdT = cls._dPdT_sat(T)
    h = alfa + T / rho * dpdT * 1000
    return h
