Final answer:
Observing the operation of air vents or air admittance valves and ensuring that they're functioning properly is crucial in making sure the drainage system maintains proper flow rate and air pressure.
Step-by-step explanation:
To ensure the drainage system is operating correctly once connected, it is important to observe several key elements. Sinks often include devices designed to increase the flow rate of water, which can be air vents or other mechanisms. These devices work by allowing air to move freely within the drain system, helping to avoid vacuum formations that would otherwise slow the flow of water. Air-filled tubes, also known as vent pipes or air admittance valves, are installed near water faucets and are needed to maintain proper air pressure within the plumbing system. This helps to speed the flow of water and prevent backflow, ensuring that the drainage system functions efficiently and effectively.