What does a pressure-reducing valve do?

A pressure-reducing valve is designed primarily to decrease water pressure entering a plumbing system. Its main function is to take incoming high-pressure water from the main supply line and reduce that pressure to a more manageable level that can be safely handled within the plumbing fixtures and pipes of a building. This is essential to prevent damage to appliances and plumbing infrastructure, which can occur if they are subjected to excessively high pressures. By maintaining a controlled and lower outlet pressure, these valves help extend the lifespan of plumbing components and ensure consistent performance across the system.

While the other options mention increasing pressure, maintaining constant pressure, or regulating temperature, they do not accurately describe the primary function of a pressure-reducing valve. This valve is specifically engineered to decrease pressure to avoid the issues associated with high pressure rather than to increase or maintain it.