A high-pressure cylinder containing $\mathrm{N}_{2}$ at $200 \mathrm{psig}$ and $70^{\circ} \mathrm{F}$ is connected by $1 / 4 \mathrm{in}$. ID stainless steel tubing, $20 \mathrm{ft}$ long, to a reactor in which the pressure is $15 \mathrm{psig}$. A pressure regulator at the upstream end of the tubing is used to control the pressure in the reactor, and hence the flow rate of the $\mathrm{N}_{2}$ in the tubing.

(a) If the regulator controls the pressure entering the tubing at $25 \mathrm{psig}$, what is the flow rate of $\mathrm{N}_{2}$ (in scfm)?

(b) If the regulator fails so that the full pressure from the cylinder is applied at the tubing entrance, what will be the flow rate of the $\mathrm{N}_{2}$ into the reactor (in scfm)?