Dual vs Tandem Pumping: Which statement describes tandem pumping?

• A. Discharge-to-intake, where the first pumper feeds the second to boost pressure
• B. Intake-to-intake sharing a source
• C. Pumpers connected in parallel to supply two separate streams
• D. Used only for fixed water supply lines

Answer: (A)

Tandem pumping is a series arrangement where the discharge from the first pumper feeds the intake of the second pumper, so the second pump develops higher pressure to the attack line. Each pump adds head, so the nozzle pressure can be greater than what a single unit could achieve, though the overall flow is governed by the second pump’s capacity and the losses in the piping between the two units. This setup is used when a single pump can’t reach the required pressure because of distance, elevation, or friction losses along a long hose lay. The other scenarios describe different concepts: sharing a source to increase flow, pumping in parallel to increase flow to two streams, or applying tandem pumping only to fixed water lines, which doesn’t capture the series pressure-boosting arrangement.