Which size open receptacle can receive discharge from up to two pedicure chairs?

The correct answer is based on plumbing codes and the required drainage capacity for specific applications, such as pedicure chairs. Each pedicure chair typically has a discharge that requires adequate drainage to prevent clogs and ensure proper flow. A 3-inch open receptacle is designed to accommodate the flow from two pedicure chairs effectively, as it provides sufficient volume and capacity for the discharge, allowing for optimal drainage.

Using smaller sizes, such as 1-inch or 2-inch, may lead to potential issues with drainage capacity, including backups or slow drainage, which could compromise hygiene and efficiency. A 4-inch opening, while sufficient, is generally not necessary for this application and would not be compliant with practices focusing on efficient and adequate drainage without over-sizing. Therefore, the 3-inch receptacle strikes the right balance for accommodating the expected discharge from two pedicure chairs without risking drainage problems.