A flanged ball valve is a quarter-turn shut-off valve with integral flanges that bolt to mating pipeline flanges via studs, nuts and a flange gasket. Inside, a perforated sphere rotates 90° between open and closed. In the open position the bore aligns with the pipe for full flow; a quarter turn closes the valve completely. Compared to a threaded ball valve, the flanged connection handles higher pressures, larger nominal sizes and is easier to maintain in-line — the valve lifts out of the flange joint without disturbing the pipework.