What is the minimum required pressure for potable water systems as per UPC?

The minimum required pressure for potable water systems, as per the Uniform Plumbing Code (UPC), is indeed 20 psi. This requirement ensures that there is adequate pressure for the supply of water to fixtures throughout a building. A pressure of 20 psi is necessary to guarantee that water flows properly to various outlets and can serve the needs of users effectively, such as in faucets, showers, and appliances.

Lower pressures, such as 10 psi or 15 psi, would likely lead to insufficient flow rates for normal usage, which could result in user dissatisfaction and potentially failing to meet health and safety standards in providing potable water. It is essential that plumbing systems maintain this minimum pressure to function correctly, providing reliable water service and preventing issues like backflow or diminished performance in fixtures.