Final answer:
Air-filled tubes, or air gaps, are used in plumbing systems to prevent water contamination and protect human health. They work by creating a physical separation between the water supply and the faucet. Air gaps are required by plumbing codes and standards in bars, soda fountains, and counters where food and beverages are served.
Step-by-step explanation:
In plumbing systems, air-filled tubes, also known as air gaps, are used near water faucets to prevent water contamination. They work by creating a physical separation between the water supply and the faucet, allowing air to enter and prevent backflow of contaminated water into the system.
The air gap acts as a barrier, ensuring that any potential contaminants, such as wastewater or chemicals, cannot enter the water supply. This is important in bars, soda fountains, and counters where food and beverages are served to prevent any harm to human health.
The use of air gaps is a requirement in plumbing codes and standards to maintain the safety and hygiene of water supply systems.