Georgia Septic Installer Practice Test

What is the minimum size pipe required to maintain fluid velocity at 12 gallons per minute?

1. 1 inch

2. 1 1/2 inch

3. 2 inch

4. 3 inch

The correct answer is: 1 1/2 inch

To determine the minimum size pipe needed to maintain a fluid velocity of 12 gallons per minute, it's important to consider both the flow rate and the diameter of the pipe. The size of the pipe directly affects the velocity of the fluid flowing through it; a larger diameter allows for a greater volume of fluid to pass through without increasing the velocity beyond desired limits. A 1 1/2 inch pipe is generally recognized as a practical size for residential septic systems and various plumbing applications when managing flow rates around 12 gallons per minute. This diameter allows sufficient cross-sectional area to accommodate the required flow while maintaining a fluid velocity conducive to preventing issues such as sedimentation and backflow. Pipes smaller than 1 1/2 inches may not sufficiently carry the required flow without significantly increasing the fluid velocity, which can lead to turbulence and the potential for blockages. On the other hand, larger pipes may exceed the flow requirements, but they may not be economical or necessary for the intended application. Understanding the relationship between pipe diameter, flow rate, and fluid velocity is crucial for effective septic system design and maintenance, which is why 1 1/2 inch is correctly identified as the minimum size required in this scenario.