Early in my career assisting operations at a heavy engineering plant, a senior maintenance supervisor taught me an indispensable lesson. Standing before a manifold on a bulk storage line, the pressure gauge read perfectly normal. As I reached for a hand valve, confident in the reading, he caught my wrist and tapped the glass face of the dial firmly with his knuckle. The needle flicked upward by two bars—it had stuck on a minute grain of grit."Never fall in love with a dial." he told me quietly. Sign in to read more..