At Class 1 you learned to chain two formulas together. Class 2 problems add a third link — and that third link is usually where an operator's chain breaks, because it requires carrying a value through a unit conversion buried in the middle of the problem rather than at the start or end. This guide covers three of the most common three-step chains in distribution process control: sizing a tank fill or drain time from a percent-full reading, tracing pressure loss along a pipeline once friction is added to elevation, and turning raw production and consumption numbers into a water loss percentage. Master these and you'll recognize the pattern in almost any multi-step distribution problem you're handed.
Step Chain 3: Storage Tank Volume → Fill or Drain Time
Tank problems at this level rarely give you "empty" or "full" — they give you a percent level, a target percent level, and a