A combination waste and vent stack with a diameter of two inches shall not receive the discharge from which of the following?

In a plumbing system, a combination waste and vent stack plays a crucial role in both draining wastewater and providing venting to maintain proper air pressure. The diameter of the stack significantly impacts its ability to handle the flow of water and prevent issues such as backpressure or water siphoning from traps.

A two-inch diameter combination waste and vent stack is generally suitable for light to moderate drainage loads. When considering the discharge from various fixtures, kitchen sinks are typically associated with a higher volume of wastewater, including food particles, grease, and other substances that can lead to clogs and backflow issues if not appropriately managed. This flow requires a larger pipe diameter to accommodate the potential volume and prevent blockages.

In contrast, a bathroom sink, shower, or washing machine typically generates less wastewater compared to a kitchen sink. These fixtures can adequately operate with the two-inch stack, as their flow rates and the nature of the discharge are less demanding.

Thus, while a two-inch combination waste and vent stack can accommodate the needs of a bathroom sink, shower, or washing machine, it is not sufficiently sized to effectively handle the discharge from a kitchen sink, which is why it is not recommended to connect it directly to that size of stack. This understanding of fixture discharge, stack