"Page 691," she said.

"But the vendor's data sheet says 2.0 is the minimum," Priya countered.

The fix was not a new distributor. It was a small bypass line and a recirculation pump to increase the head. Total cost: $12,000 and two days of welding.

He nodded. "The book is never wrong," he whispered. "Only the engineer who stops reading it."

She read his notes. Then she smiled.

Tonight, that compass was pointing toward ruin.

The problem was the alkylation unit’s quench tower. For three weeks, the pressure drop across the middle bed had been climbing like a fever. The junior engineers had offered solutions: add a anti-fouling agent, bypass the bed, increase the reflux ratio. Each suggestion had been met with a quote from Chapter 14 (Heat Transfer Equipment) or Chapter 22 (Safety and Loss Prevention). "Show me the design calculation," Aris would say, tapping the book. "Show me the margin."