How should the waste pipe of a dishwasher attach to the kitchen sink system?

When connecting the waste pipe of a dishwasher to the kitchen sink system, it is essential to ensure that it is installed correctly to prevent any potential backflow and to facilitate proper drainage. The use of a wye branch fitting is the appropriate method because it allows for a smooth transition of wastewater flow from the dishwasher into the sink's drainage system.

A wye branch fitting creates a point where the waste pipe from the dishwasher can enter the sink's drainage line at an angle, ensuring that debris and wastewater flow smoothly without causing blockages. This fitting also helps maintain the necessary water seal and prevents any siphoning that could lead to unpleasant odors or the backflow of waste into the dishwasher.

Other methods, such as connecting directly to the sink faucet or a separate disposal unit, do not comply with the recommended plumbing practices and might compromise the drainage system's effectiveness. Additionally, any option stating that the dishwasher should not connect to the sink's system is not a viable solution, as dishwashers must have a proper drainage method in place to ensure their effective operation.