A ball valve is a quarter-turn valve, meaning that the handle only needs a 90° turn to fully open or close the valve. The main components of a ball valve are The stem, connects to the ball, The ball sits on the ball valve seat creating the seal. The O-ring stem seals are used to prevent leakage. All of these components are within the valve housing. The ball has a bore running through it. Under normal operation, the bore is either aligned with the valve ports to allow flow, or perpendicular to the ports to block flow.
Ball valves are both used to turn on or off the flow, though, can also function in a partially open or closed state to modulate the flow. This flow regulation is achievable due to the globe valve’s disc sitting parallel to the flow. The linear flow rate achieved by globe valves is higher than that achieved by ball valves, and reduces the effects of a water hammer.