What is defined as any pipe receiving discharge from any fixture except water closets?

The correct answer is waste pipe, which is specifically defined as any pipe that carries wastewater away from fixtures, with the exception of toilets or water closets. Waste pipes are crucial in plumbing systems as they are responsible for transporting liquid waste and non-fecal material to a drainage system, such as a sewer or septic system.

Understanding the distinction is important; waste pipes typically handle the effluent from sinks, showers, bathtubs, and other fixtures, ensuring that waste is efficiently removed from the premises without contamination.

In contrast, drain pipes are often a term that may encompass both waste pipes and pipes that primarily handle the flow from fixtures, including those that might collect water from water closets. Venting pipes serve a different purpose by allowing air into the plumbing system to maintain pressure, facilitating better drainage. Supply pipes are responsible for bringing clean water to fixtures and are not involved in carrying away waste, which further defines the functions within a plumbing system.