Master Plumber Practice Exam

The correct choice reflects the requirement for the minimum aggregate cross-sectional area of vents in a plumbing system. For a 4-inch diameter sewer pipe, the minimum venting area is directly related to the size of the drainage system it serves, ensuring that there is adequate ventilation for proper function and to prevent the buildup of harmful gases.

To determine the minimum aggregate cross-sectional area, the area of a circle is calculated using the formula A = πr², where A is the area and r is the radius. For a 4-inch pipe, the radius is 2 inches. Plugging into the formula gives:

A = π(2 inches)² = π(4 square inches) ≈ 12.56 square inches.

This calculation shows that for a 4-inch sewer system, the minimum aggregate cross-sectional area of vents must be at least 12.56 square inches to ensure effective pressure equalization and proper drainage function. Thus, this is the correct answer for the question regarding minimum venting requirements.