A backwater valve installed in a manhole more than 2 feet deep requires the diameter of the manhole to be at least _____________ inches?

A backwater valve in a manhole that is more than 2 feet deep must be installed in a manhole with a diameter of at least 48 inches to ensure proper access and functionality. This size is critical because it allows for the necessary space to accommodate the valve, as well as to facilitate maintenance and potential repairs. The larger diameter provides sufficient room for a professional plumber or maintenance technician to work comfortably in the confined space of the manhole.

Additionally, the code establishes this dimension to ensure that the operational integrity of the plumbing system is maintained. A manhole too small would make it difficult to properly install or service the valve, potentially leading to increased risks of blockages or failures in the system. The requirement for a 48-inch diameter also reflects best practices for safety and effective drainage management in plumbing installations, especially in deeper setups where the potential for backflow is more pronounced.