Illinois Plumbing Code Practice Exam 2026 - Free Plumbing Code Practice Questions and Study Guide

The correct size for waste outlets for kitchen sinks, according to the Illinois Plumbing Code, is indeed 1 1/2 inches. This dimension is established to effectively handle the volume of waste water and potential solids generated by kitchen activities, ensuring that drainage systems work efficiently and reduce the risk of clogs.

The 1 1/2-inch outlet size balances adequate flow capacity with the physical constraints and plumbing system requirements typically found in residential settings. Using a larger size might not offer significant benefits and could complicate installations, while a smaller size risks inadequate drainage.

This dimension aligns well with common plumbing practices and the requirements set forth in the code, promoting both safety and efficiency in waste management systems across kitchen environments.