What is meant by shut-off head, or dead head, in pumping?

• A. When the pump reaches maximum pressure with no flow
• B. When the pump is turning without oil lubrication
• C. When the discharge line is blocked
• D. When the suction is flooded

Answer: (A)

Shut-off head is the maximum pressure (head) a pump can develop when there is no flow. It occurs when the discharge path is blocked or closed, so the pump keeps building pressure even though nothing is moving. The best description among the options is the one that states the pump reaches maximum pressure with no flow. The other statements describe unrelated aspects (lubrication, suction conditions) or a blocked discharge without illustrating that it’s the maximum pressure the pump can generate at zero flow. This concept is important for understanding pump performance curves and what happens when flow is halted.