Heat Exchanger Design for Mechanical Static and Package Engineering Professionals

A: A. You're standing in the unit. No flow with rising temperature usually means no flow. Blinds and closed block valves cause exactly this and the DCS won't tell you. B. Tag mapping errors exist, but you don't chase software before ruling out steel-in-the-ground. C. FAT proves nothing about current valve line-up at 02:00. D. Relief settings don't explain zero indicated flow and heating at the same time.

A: A. 200 m3/h is ~55.6 kg/s. Cp ~4.2 kJ/kg-K. Multiply by 10 K and you're just over 2 MW. B. That's a decimal slip on mass flow. Happens a lot at night. C. Fouling doesn't double sensible heat. D. Effectiveness matters for approach, not for this basic energy balance.

A: A. Missing sealing strips let shell fluid short-circuit, killing heat transfer without changing fouling numbers. B. Fouling would raise tube-side delta T, not flatten it. C. Higher shell flow usually improves duty, not degrades it. D. One bad transmitter doesn't explain sustained poor performance confirmed by process data.

A: A. Hydrotest margin is about proving the pressure boundary under worst credible static stress. B. Thermal stress isn't assessed with cold water. C. Relief failure is a separate protection layer. D. Nozzle loads are mechanical checks, not hydrotest objectives.