Reverse or Direct Acting a. In an open surge tank, the liquid level is maintained by manipulating the flow out of the tank via a control valve on the effluent stream. To prevent any liquid from spilling over, the control valve is set to fail open. Determine the controller action required for this process setup with suitable explanation and justification. V-100 FLAM uc 200 300 LAL 300. - LY 200 LCV 100 b. Inside a reactor, an exothermic reaction takes place. The temperature of the reactor is controlled by manipulating the flow of cooling water that flows through a cooling water jacket. Justify, for safety reasons, the failure mode of the control valve. Determine the controller action in a temperature control system for the control of reactor temperature.