What is the minimum size of a fixture water supply pipe for a flush-valve urinal?

The minimum size of a fixture water supply pipe for a flush-valve urinal is 3/4 inch. This requirement is established to ensure that the urinal receives an adequate flow of water to operate effectively. Flush-valve urinals typically require a higher water volume for flushing compared to other types of fixtures, such as gravity-flush urinals.

Using a 3/4 inch pipe allows for sufficient water pressure and flow rate necessary for the valve to function properly, thus preventing issues such as inadequate flushing, clogs, or malfunction of the flush system. A pipe sized smaller than this could potentially lead to reduced performance of the urinal, while larger sizes may lead to increased costs and unnecessary complexity in the plumbing system.

In plumbing codes and regulations, these specifications help to standardize installations to promote efficiency and reliability in plumbing design and failure prevention.