What is the formula to size an interceptor?

The formula for sizing an interceptor involves calculating the volume of the interceptor using the dimensions of length, width, and depth. The specific calculation of multiplying length by width by depth provides the total volume in cubic inches. To convert this volume into gallons, which is a common unit for sizing plumbing interceptors, the result is then divided by 231. This is because there are 231 cubic inches in one gallon.

Using this approach ensures that the interceptor can effectively handle the flow and solid waste produced in a given system, which is essential for proper functioning and compliance with plumbing codes. This focus on accurate volume calculation is critical for maintaining the system's efficiency and preventing potential issues such as backups or insufficient waste removal.

The other options provide alternative methods that do not align with the standard practice for calculating an interceptor's size. They either utilize incorrect arithmetic operations or fail to address the necessary conversion to proper volumetric units relevant to plumbing systems.