Master Plumber Practice Exam 2025 - Free Plumber Practice Questions and Study Guide

The maximum length for a 1-1/2-inch vent pipe is based on plumbing codes that ensure proper venting for drainage systems. The correct choice reflects the standard guidelines that establish the limitations for vent pipe lengths to maintain adequate air flow and proper drainage performance.

When considering vent pipes, the objective is to prevent negative pressure in the drainage system, allowing waste to flow freely while ensuring sewer gases can escape without issue. For a 1-1/2-inch vent pipe, the guideline states that to effectively vent the system without risking underperformance, the maximum length should ideally not exceed 60 feet. This length is derived from calculations involving the size of the pipe, the number of fixture units served, and the overall system design.

Understanding these codes and guidelines is crucial for plumbing professionals, as it helps ensure compliance and functionality in plumbing systems.