What is the advantage of a reduced bore valve over a full bore valve?
Reduced bore ball valves have a smaller ball size than full bore ball valves and consequently the housing (casting or forging) is smaller for reduced bore ball valves.
This results in lower construction costs and lower weight. The smaller ball size also results in lower actuating torque and lower actuator costs for the valve. The pressure drop across a reduced bore valve will be marginally higher than for a full bore valve.
Where the pressure drop becomes very critical, full bore valves are supplied instead of reduced bore valves. Full bore valves are also supplied for special applications, such as in pipelines to facilitate pigging and hot-tapping applications.