Air at $100 \mathrm{psia}$ and $60^{\circ} \mathrm{F}$ is being controlled through a venturi control valve. The backpressure at the valve discharge is $P_{2}=30 \mathrm{psia}$. The flow rate through the valve at its maximum opening is to be found, using the equations from ISA-75.01.01 and numerical integration. The parameters provided by the valve company for a wide-open valve are $C_{1}=14.1$ and $X_{T}=0.1254$ (the low value of $X_{T}$ indicates that it is a high-recovery valve). Additionally, $F_{\gamma}=1.0$ (value for air); $C_{\gamma}=355.9$ (value for air); molecular weight for air $=29$; ideal gas compressibility $Z=1.0$; and specific heat ratio, $\gamma=1.4$ calculated at the inlet pressure and temperature.