Illinois Plumbing Code Practice

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Prepare for the Illinois Plumbing Code Exam with our comprehensive quiz that includes flashcards and multiple-choice questions to bolster your understanding of plumbing standards and regulations. Gear up for your test!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

How many times the diameter of the fixture drain or drainage pipe served must the air gap between an indirect waste in the drainage system be at least?

1x's 1
2x's 2
3x's 3
4x's 4

The correct answer is: 1x's 1

The correct answer is that the air gap must be at least two times the diameter of the fixture drain or drainage pipe served. This requirement is crucial in preventing back-siphonage and ensuring that contaminants do not enter the potable water supply. In plumbing codes, the air gap acts as a physical separation between the outlet of the drainage system and the flood level of the receiving fixture. By maintaining an air gap of at least twice the diameter of the drain, it creates sufficient space to prevent any potential backflow, thus protecting public health. This safety measure is essential in indirect waste systems, where proper drainage and venting are necessary to avoid any risks associated with wastewater contaminating drinking water systems.