What is the minimum air gap required for a sink to prevent backflow?

What is the minimum air gap required for a sink to prevent backflow?

• A. ¾ inch
• B. 1 inch
• C. 2 inches
• D. 3 inches

Answer: (B)

The minimum air gap required for a sink to prevent backflow is 1 inch. An air gap is a physical separation between the end of a water supply tube and the flood level rim of a fixture, which is critical in preventing contaminated water from siphoning back into the potable water supply. In plumbing codes, a 1-inch air gap is commonly specified for sinks and similar fixtures because it provides a sufficient barrier to prevent potential backflow incidents. By maintaining this distance, the risk of contamination through back siphonage is minimized, ensuring that the water supply remains clean and safe for use. The specific measurement of 1 inch is supported by plumbing standards, which recognize it as an effective means of ensuring proper hygiene and safety in residential plumbing systems.

The minimum air gap required for a sink to prevent backflow is 1 inch. An air gap is a physical separation between the end of a water supply tube and the flood level rim of a fixture, which is critical in preventing contaminated water from siphoning back into the potable water supply.

In plumbing codes, a 1-inch air gap is commonly specified for sinks and similar fixtures because it provides a sufficient barrier to prevent potential backflow incidents. By maintaining this distance, the risk of contamination through back siphonage is minimized, ensuring that the water supply remains clean and safe for use. The specific measurement of 1 inch is supported by plumbing standards, which recognize it as an effective means of ensuring proper hygiene and safety in residential plumbing systems.