1. Specify whether an air-to-open or air-to-close control valve should be used in the following services. Justify your answer.
i. A cooling water stream to a highly exothermic CSTR.
ii. A steam flow to a distillation reboiler.
iii. A steam flow to an extrusion machine to keep the polymer in liquid form.
iv. A wastewater stream from treatment system that is being released into a nearby river.
v. Reactants flow into a catalytic reactor.