What is the minimum diameter of waste outlets for sinks?

The minimum diameter of waste outlets for sinks is typically recognized as 1.5 inches. This standard size is utilized to ensure adequate drainage while preventing clogs and allowing proper functioning of the plumbing system. The 1.5-inch diameter is particularly suitable for kitchen sinks, lavatory sinks, and other types of sinks designed for residential use.

Using a diameter smaller than this could lead to problems such as slow drainage or increased likelihood of clogs, as the waste and water flow would be insufficient. Therefore, a 1.5-inch outlet accommodates typical discharge requirements efficiently in residential plumbing systems, aligning with plumbing codes and standards.

In summary, while there may be various sizes for different applications, the 1.5-inch size is the minimum necessary for effective waste drainage in sinks.