What condition prevents cavitation in a deadheaded pump?

What condition prevents cavitation in a deadheaded pump?

• A. Provide Safe Flow Rate With Permanent Flow Path
• B. Increase Pump Speed
• C. Close The Discharge Valve
• D. Add More Heat

Answer: (A)

Cavitation happens when local pressure in the liquid falls below its vapor pressure, causing vapor bubbles to form and collapse, which can damage the pump. The pressure drop that leads to cavitation is tied to the amount of flow and the presence of a continuous path for the liquid to move through the pump. Keeping a safe flow rate with a permanent flow path means the pump always has some circulation, so the suction side pressure remains high enough and the head losses are managed. This maintains enough Net Positive Suction Head (NPSH) available to exceed what the pump requires (NPSH_r), preventing the conditions that cause cavitation even if the discharge line is otherwise restricted. In contrast, closing the discharge valve stops flow entirely, which can push the system into a shut-off condition and promote cavitation. Increasing speed without a guaranteed flow path can worsen pressure variations and cavitation risk, and adding heat raises the liquid’s vapor pressure, making cavitation easier to initiate.

Cavitation happens when local pressure in the liquid falls below its vapor pressure, causing vapor bubbles to form and collapse, which can damage the pump. The pressure drop that leads to cavitation is tied to the amount of flow and the presence of a continuous path for the liquid to move through the pump.

Keeping a safe flow rate with a permanent flow path means the pump always has some circulation, so the suction side pressure remains high enough and the head losses are managed. This maintains enough Net Positive Suction Head (NPSH) available to exceed what the pump requires (NPSH_r), preventing the conditions that cause cavitation even if the discharge line is otherwise restricted. In contrast, closing the discharge valve stops flow entirely, which can push the system into a shut-off condition and promote cavitation. Increasing speed without a guaranteed flow path can worsen pressure variations and cavitation risk, and adding heat raises the liquid’s vapor pressure, making cavitation easier to initiate.