A continuous flow reactor vessel contains a liquid reacting mixture with a density of $0.85 \mathrm{~g} / \mathrm{cm}^{3}$ and a viscosity of $7 \mathrm{cP}$ at $1 \mathrm{~atm}$ pressure. Near the bottom of the vessel is a $1 \frac{1}{2} \mathrm{in}$. outlet line containing a safety relief valve. There is $4 \mathrm{ft}$ of pipe with two $90^{\circ}$ elbows between the tank and the valve. The relief valve is a spring-loaded lift check valve, which opens when the pressure upstream of the valve reaches $5 \mathrm{psig}$. Downstream of the valve is $30 \mathrm{ft}$ of horizontal pipe containing four elbows and two gate valves that empties into a vented catch tank. The check valve serves essentially as a level control for the liquid in the reactor because the static head in the reactor is the only source of pressure on the valve. Determine

(a) The fluid level in the reactor at the point when the valve opens

(b) When the valve opens, the rate (in gpm) at which the liquid will drain from the reactor into the catch tank