Journeyman Plumber Practice Exam

For a coin-operated laundry, the required outlet size of a floor drain is typically 3 inches. This size is dictated by the high volume of water that can be discharged during washing cycles, as well as the need to accommodate any potential sediment or debris. A 3-inch outlet allows for adequate drainage flow to prevent water from backing up and ensures the efficient operation of the laundry equipment.

Smaller outlet sizes, such as 2 inches, may not provide sufficient drainage, especially during peak usage times, leading to potential clogs and overflow issues. Larger sizes, such as 4 or 5 inches, may also be unnecessarily large for typical laundry operations, which could complicate installation and possibly increase costs without providing significant benefits. Thus, a 3-inch outlet strikes the right balance for the requirements of a coin-operated laundry facility.