Relay pumping is used when?

• A. Using two or more pumps to move water from a distant source to meet demand, used when a single pump cannot supply sufficient water.
• B. When a single pump is sufficient to meet demand.
• C. Only for interior operations.
• D. When pumping from a water tower.

Answer: (A)

Relay pumping is about using multiple pumps in sequence to move water when a single pump can't supply enough water or pressure. In practice, you’d have one pump draft from a distant source and push the water into another pump, which then continues the discharge toward the destination. This setup helps overcome distance, friction losses in the hoses, and elevation changes that reduce flow. It’s not chosen when one pump can meet the demand, nor is it limited to interior operations, and it isn’t specifically about pumping from a water tower, which often involves gravity feed rather than a staged, pressurized relay.