Ball valve made of solid elements offers high durability, and have the ability to function perfectly even after long idle time. It has a sphere made of brass, stainless steel, or chrome plated brass, embedded inside the conduit. On the top of the sphere is a lever attached which can move in a quarter turn only. When the level lies parallel to the pipe, the sphere allows water to flow. When the lever is perpendicular to the pipes the solid sphere blocks the water flow. The water flow is controlled by moving the lever from 0 to 90 degree in terms with the pipe with whom it is attached. 

On the flip side though you have the provision to make water flow partially through the pipes by keeping the lever in between 2 limits, but due to water pressure, water pipes might distort.

The advantage of this kind of valves is that you can easily and quickly open or close it. However, water hammers the sphere and the sides of the pipe all the time, except when it is fully open to channelize the water.