Journeyman Plumber Practice Exam

For a sump pump with a discharge of 60 gallons per minute (gpm) and a length of 78 inches, the required vent pipe diameter is determined based on several key factors, including the flow rate and the application of the vent pipe. A vent pipe is critical for allowing air to enter the drainage system, which helps to prevent vacuum conditions as water is pumped out.

In this scenario, a 2-inch diameter vent pipe is suitable for accommodating the flow from a sump pump operating at 60 gpm. The sizing guidelines for vent pipes are typically based on flow rates and the specific applications they serve. A vent pipe of this diameter can handle the air flow generated by the discharge from the sump pump effectively, which is essential for maintaining proper drainage and preventing any potential blockages or issues in the plumbing system.

Choosing a larger diameter than necessary could unnecessarily increase costs and installation complexity, while a smaller diameter might not provide the required ventilation, leading to possible pressure issues. Therefore, the selection of a 2-inch diameter pipe adequately balances performance, safety, and practicality for this specific application.