What is the minimum air gap requirement for a water supply inlet?

The minimum air gap requirement for a water supply inlet is critical to prevent contamination of the potable water supply. The correct answer, which indicates that the air gap should be twice the diameter of the water supply inlet, is based on established plumbing codes and health standards. This requirement ensures that there is a sufficient distance between the water supply and any potential backflow contaminants.

By specifying an air gap that is twice the diameter of the inlet, it is created a buffer zone that reduces the risk of siphoning or backflow due to changes in water pressure. This is essential in protecting the integrity of the water supply, especially in situations where contaminants could enter the system.

In plumbing practices, such attention to backflow prevention is vital for safeguarding public health. An air gap that meets these standards helps to avoid situations where dirty water and other substances could potentially reverse flow back into clean water systems, thus maintaining the safety and quality of the drinking water supply.