What is the maximum number of fixture units a 6 inch horizontal drain can accommodate?

The correct response indicates that a 6-inch horizontal drain can accommodate a maximum of 700 fixture units, which is based on industry standards for plumbing design. The capacity of a drain is determined by its diameter, and larger pipes can handle more fixture units due to their increased flow area.

For a 6-inch drain, the 700 fixture units are set according to various plumbing codes that stipulate how many units can flow through without causing issues like clogs or excessive buildup. This value considers factors such as the potential for simultaneous operation of fixtures and the overall hydraulic performance of the drain system.

In contrast, the other choices suggest higher limits that exceed the established guidelines and plumbing codes commonly accepted in the field, leading to scenarios that could compromise the system's effectiveness in managing waste and drainage. Understanding these limits is crucial for ensuring proper plumbing system design and function.