Massachusetts Plumbers Journeyman Practice Exam

How should the building water distribution system be designed for fluctuating street main pressures?

1. For the maximum street pressure

2. For the average street pressure

3. For the minimum pressure available

4. For a constant pressure level

The correct answer is: For the minimum pressure available

The design of a building water distribution system should take into account the lowest possible pressure that may be encountered, which is why opting for the minimum pressure available is crucial. This ensures that even during periods of low street main pressure, the system can still provide adequate water flow and pressure to meet the building's needs. By designing for the minimum pressure, you can prevent issues such as insufficient water pressure during peak usage times, which could affect performance and lead to dissatisfaction among the occupants. Designing for maximum or average pressures may not guarantee functionality during lower pressure conditions, leaving the building vulnerable during times of fluctuating supply. Additionally, aiming for a constant pressure level may not reflect the reality of changing conditions in the municipal water supply, potentially leading to system failures or inefficiencies. Thus, ensuring the system is capable of operating effectively at minimum pressure is the most reliable approach.