What is the minimum distance above the bottom of the tank that an anti-vortex device must be installed?

What is the minimum distance above the bottom of the tank that an anti-vortex device must be installed?

• A. 4 Inches
• B. 8 Inches
• C. 10 Inches
• D. 6 Inches

Answer: (D)

Anti-vortex devices are placed on the tank fill line to prevent the formation of a swirl at the inlet when water is drawn, which could pull in air and disrupt the supply. The minimum distance above the bottom keeps the device out of the sediment layer and in cleaner, more stable water, so it can reliably break any developing vortex and maintain a proper prime. Six inches is the standard minimum because it provides enough separation from the tank floor to avoid sediment clogging while still ensuring effective operation. Placing it closer (too near the bottom) increases the risk of sediment intake and reduced performance, while larger gaps aren’t required to meet typical requirements.

Anti-vortex devices are placed on the tank fill line to prevent the formation of a swirl at the inlet when water is drawn, which could pull in air and disrupt the supply. The minimum distance above the bottom keeps the device out of the sediment layer and in cleaner, more stable water, so it can reliably break any developing vortex and maintain a proper prime. Six inches is the standard minimum because it provides enough separation from the tank floor to avoid sediment clogging while still ensuring effective operation. Placing it closer (too near the bottom) increases the risk of sediment intake and reduced performance, while larger gaps aren’t required to meet typical requirements.