What is the maximum number of residential sinks that can be used with a 2-1/2" vent pipe?

The maximum number of residential sinks that can be used with a 2-1/2" vent pipe is based on plumbing codes that specify vent sizing according to the number of fixture units connected to it. A 2-1/2" vent pipe is capable of serving a significant number of fixture units, as its diameter allows for adequate air circulation to prevent siphoning of traps and ensure that waste can flow away properly.

In most plumbing codes, each residential sink is assigned a specific number of fixture units, and the vent pipe must be adequately sized to accommodate these units without causing pressure problems such as backflow or inadequate drainage. A 2-1/2" vent can typically accommodate up to 24 fixture units, which aligns with the correct answer. Thus, you can effectively connect up to 24 residential sinks to a 2-1/2" vent pipe under normal conditions, ensuring that all sinks function properly without risking drainage issues. This capacity supports compliance with safety and operational standards within plumbing systems.