What is the minimum size of a floor drain receiving the discharge from a 2 inch RPZ?

The minimum size of a floor drain receiving the discharge from a 2-inch Reduced Pressure Zone (RPZ) valve is appropriately set at 3 inches. This requirement is based on plumbing codes and best practices, which aim to ensure that the drainage system can effectively handle potential backflow or overflows that can occur from a device like an RPZ.

An RPZ is designed for health hazard applications where potable water may be contaminated and needs proper drainage to protect the public water supply. The sizing of the floor drain is crucial for maintaining an efficient drainage system that can handle a higher flow rate without risk of blockage or flooding.

A drain that is too small could lead to inadequate drainage, creating potential hazards and possibly nullifying the safety benefits provided by the RPZ. Therefore, the choice of a 3-inch drain aligns with established plumbing standards to ensure safety and efficiency in the system.