When water pressure fluctuates, the water distribution system in a building must be designed for what type of pressure?

The water distribution system in a building must be designed to handle maximum pressure fluctuations. This is essential because maximum pressure represents the highest level of pressure that the system may experience due to various factors, such as sudden changes in demand, pump operation, or external influences. By designing for maximum pressure, the system ensures it can withstand unexpected surges without causing damage or failure, such as pipe bursts or leaks.

Designing for maximum pressure guarantees that all components, including pipes, valves, fittings, and fixtures, are capable of handling the most extreme conditions they may encounter over the lifespan of the installation. This approach helps in maintaining consistent water delivery without compromising safety or functionality, even when peak demand occurs.

In contrast, minimum, average, and peak pressures do not account for the full range of operational stresses the system might encounter, especially in fluctuations. Therefore, designing for maximum pressure is crucial for ensuring the long-term reliability and integrity of the plumbing system.