What is the minimum diameter required for a drain connected to food-waste disposers?

• A. 1 inch
• B. 1 ¼ inches
• C. 1 ½ inches
• D. 2 inches

Answer: (C)

The correct answer is based on plumbing codes and standards that dictate the necessary specifications for drains in residential plumbing systems. For drains connected to food-waste disposers, a minimum diameter of 1 ½ inches is required. This specification ensures that the drainage system can adequately handle the high volume of waste and water discharged from food-waste disposers, which often include a mixture of solid food particles and liquid waste.

A larger diameter, such as 1 ½ inches, is advocated as it helps prevent clogs and allows for proper flow rates, minimizing the chance of backflow or blockages. A diameter smaller than this could lead to insufficient drainage performance and potential plumbing issues. Consequently, plumbing codes enforce this standard to ensure that residential systems function effectively without frequent maintenance problems.