What type of valve is typically used to control the flow of water in HVAC systems?

The type of valve commonly used to control the flow of water in HVAC systems is the ball valve or gate valve. Ball valves are favored for their ability to provide a tight seal and a straight-through flow path, which minimizes pressure drop and allows for quick on/off control of the flow. They can handle high pressures and temperatures, making them ideal for various HVAC applications.

Gate valves are also effective for controlling flow since they allow for full flow with minimal resistance when fully open. However, they are more typically used for isolation purposes rather than throttling.

The other types of valves mentioned serve different purposes within HVAC systems. Butterfly valves and check valves are better suited for regulating flow and preventing backflow, respectively. Pressure relief valves are designed to prevent overpressure situations, while mixing valves are used to blend fluids at different temperatures. Solenoid and proportional valves are primarily utilized in applications that require automated control and fine adjustments, which are not the main focus when controlling water flow in standard HVAC systems.