Material Science & Engineering

A: Picking the wrong interpretation drives misfit ferrules and leaks during SAT, and the line stalls while adapters are sourced. Tubing callouts in inch-based hygienic systems lock OD first; wall is specified, and ID is the result. That aligns with orbital weld heads, ferrule sizing, and the drawing note, while DN language belongs to pipe, not tube.

A: Skipping the surface condition risks latent corrosion that only shows up after media contact, forcing a re-passivation and OQ repeat. Passivation acceptance hinges on free iron removal; field checks start with documented test results like ferroxyl or copper sulfate. Mechanical assembly and controls matter, but they come after confirming the metal surface state.

A: Underestimating the time leads to rushed OQ runs and apparent control failures when temperatures lag. Two hundred liters is roughly 200 kg; stainless plus liquid lands near 4 kJ/kg·K dominated by the liquid. A 60 K rise needs about 48 MJ. At 5 kW, that’s around 9,600 seconds, or roughly 40 minutes, before any losses are even counted.

A: A wrong pick shows up as pitting or rouge, triggering excursions and revalidation. 316L is accepted for WFI when chemistry and surface finish are controlled; it balances corrosion resistance and cleanability. Duplex adds strength you don’t need and complicates fabrication, while carbon steel and 304L fail corrosion and hygiene expectations.