What is the minimum inside diameter for a manhole used for a cleanout with more than one inlet?

The minimum inside diameter for a manhole used for a cleanout with more than one inlet is 54 inches. This measurement is specified in plumbing codes to ensure adequate access and maintenance for systems with multiple inlets. A manhole of this size allows for sufficient space to accommodate cleaning equipment and personnel who need to work inside the manhole, promoting effective maintenance and minimizing the risk of clogging.

Using a diameter of 54 inches is critical because manholes serve as access points for cleaning and inspections, particularly in complex systems where multiple lines might converge. A smaller diameter would restrict access, making it difficult to perform necessary maintenance tasks. Additionally, a larger diameter, while providing more space, may not be required or efficient in many scenarios, resulting in unnecessary construction costs. Thus, while ensuring functionality and safety, 54 inches represents a balance between utility and efficiency in plumbing design.