What is the minimum distance above the bottom of a tank at which an anti-vortex plate must be installed?

What is the minimum distance above the bottom of a tank at which an anti-vortex plate must be installed?

• A. 2 inches
• B. 4 inches
• C. 8 inches
• D. 6 inches

Answer: (D)

Anti-vortex plates are used on suction inlets to prevent the swirl that forms when water is drawn into a pump, which can create a surface vortex and pull air into the system, risking loss of prime. Placing the plate at least six inches above the bottom keeps it in a clean portion of the water and in the right flow region to disrupt the developing vortex before it reaches the suction. This distance helps prevent sediment or debris at the very bottom from clogging the plate, while ensuring the plate remains submerged and effectively stabilizes the inlet flow under typical tank conditions. If it’s closer than six inches, sediment and bottom debris are more likely to interfere with the plate; if it’s placed higher than six inches, it may be less effective at breaking up the vortex at the suction. Therefore, six inches is the minimum distance.

Anti-vortex plates are used on suction inlets to prevent the swirl that forms when water is drawn into a pump, which can create a surface vortex and pull air into the system, risking loss of prime. Placing the plate at least six inches above the bottom keeps it in a clean portion of the water and in the right flow region to disrupt the developing vortex before it reaches the suction. This distance helps prevent sediment or debris at the very bottom from clogging the plate, while ensuring the plate remains submerged and effectively stabilizes the inlet flow under typical tank conditions. If it’s closer than six inches, sediment and bottom debris are more likely to interfere with the plate; if it’s placed higher than six inches, it may be less effective at breaking up the vortex at the suction. Therefore, six inches is the minimum distance.