Pilot Plant and Scale-up Studies

A: A: Matches the alarm that 'shouldn't be possible'. Redundancy exists only if both valves can move. Loss of air takes one out and halves capacity. B: Would bias level, but you'd see steady offset, not a sudden HH coincident with air issues. C: A cracked bypass drains level, it doesn't drive HH unless you're misreading trends. D: Internals affect carryover downstream, not vessel level climbing against control.

A: A: Handles wet chlorides better during idle periods when oxygen sneaks in. B: Linings hate thermal cycling and pilot plants cycle a lot; holidays become leaks. C: 304 takes chloride pitting early; temperature isn't the only driver. D: Overkill here and introduces chipping risk during frequent modifications.

A: A: 1.2 / 3.6 gives 0.333 h, that's 20 min. Straight definition. B: Vapor holdup changes effective volume only if reaction is in vapor; not stated. C: Safety factors don't change the reported residence time, only design margins. D: Unit handling error that pops up in reviews, but math doesn't hold.

A: A: Cold loop check catches wiring, logic, and valve action without adding risk. B: Heating comes later; you're skipping interlocks. C: Calibration happens before circulation unless process conditions are required. D: FAT doesn't cover field wiring or as-built terminations.