Process Equipment Design: Fundamentals and Applications

A: 5–10 kPa across a startup strainer is the tripwire here. Anything higher risks cavitation on first rotation. Rotation checks and logic proofs matter, but a blocked suction will damage the pump before those errors show up.

A: A doubling of ΔP with falling U points to flow area loss. Internal bypass from gasket creep usually drops ΔP while losing duty. Deformation and maldistribution show up earlier and often during startup, not gradually.

A: 0.85 is the threshold engineers miss. Effective ΔT is F×LMTD, not the inverse. Using 42 K oversizes duty; dividing by F understates area and fails performance.

A: Around 110–120% of BEP, current and NPSHr climb quickly. Pressure doesn't rise; it falls. The boundary is electrical and cavitation risk before mechanical relief.

A: Around 60–70°C is where 316L starts to fail fast in aerated chloride service. Duplex pushes that limit much higher. Allowance and coatings don't address SCC initiation.

A: MAWP at the coincident metal temperature is the compliance anchor. Relief settings and hydrotests derive from it, not the other way around.

A: Below the tray's minimum vapor velocity, liquid falls through perforations without raising ΔP. Flooding and backup would spike ΔP well before separation collapses.

A: The boundary is simple but missed in audits. CA is additive to required thickness, not absorbed by tolerance or doubled unless specified for both sides.

A: 70–80% of BEP is the common stability floor for OH2 pumps. Crossing it triggers internal recirculation and heat rise. The recycle is the protective move; the others worsen hydraulics.