PMP - Project Management Professional Training

A: That's the most common mistake — treating a deferred field check like a paperwork gap. The difference matters because conditional clearance only holds if the condition is verified before exposure to pressure. A lock-open PSV inlet is a single-point safeguard; once energy is introduced, you're already past the safe decision point.

A: That's the usual mix-up — assuming a trip solves degradation problems. The difference matters because SIL functions address acute scenarios, not long-term damage mechanisms. A high-pressure shutdown reacts to excursions; it doesn't keep you away from the edge where catalysts quietly lose activity.

A: That's the classic confusion — inlet versus outlet effects. The difference matters because excessive inlet loss starves the valve right when it needs steady flow, leading to chatter and reduced capacity. Backpressure and MAWP are separate checks handled elsewhere.

A: That's the knee-jerk reaction — chasing liquids instead of vapor load. The difference matters because delta-P spikes usually come from vapor flooding. Trimming duty addresses the cause, while reflux or pressure changes can push you closer to entrainment.