A Ball Valve is a quarter-turn shutoff valve featuring a hollow, rotating sphere with a bore that opens or closes fluid passage. Ball valves provide reliable on-off isolation in HVAC systems with minimal leakage and pressure drop.
Design and Specifications
Ball valves rotate 90 degrees to move the bore opening from full closure to full opening, providing tight sealing with minimal effort. Pressure drop is negligible when fully open (typically 0.5 psi), lower than globe and butterfly valves. Standard sizes range from 1/2-inch to 2-inch in HVAC applications, with full-port designs minimizing flow restrictions. Operating temperatures reach 250°F for standard materials, with stainless steel versions handling higher temperatures. The simple design reduces maintenance requirements and extends service life to 10-20 years.
HVAC Applications
Ball valves provide reliable shutoff and isolation for chilled water, hot water, and condenser water circuits. They serve as manual isolation valves upstream and downstream of control valves and equipment. Three-way ball valves enable diverting or mixing applications with proportional control capability. However, their on-off design makes them unsuitable for proportional flow modulation without specialized actuator configurations.