What is the primary purpose of a pressure reducing valve (PRV) in a plumbing system?

The primary purpose of a pressure reducing valve (PRV) is to maintain consistent water pressure within a plumbing system. These valves are typically installed in situations where the incoming water pressure is significantly higher than what is safe or optimal for the fixtures and appliances within the plumbing system.

By regulating and reducing the water pressure, a PRV helps to prevent potential damage to pipes, fittings, and fixtures that could occur due to excessive pressure. This consistent pressure ensures that water flows effectively to all outlets, preventing fluctuations that could lead to issues like leaks or inefficient operation of appliances. The steady pressure also enhances the longevity of the plumbing system as it minimizes the risk of bursts and wear.

In contrast, options that suggest increasing pressure, isolating flow, or controlling hot water access do not align with the function of a PRV, as their objectives do not focus on reducing and stabilizing pressure in the system.