Hydraulic ball valves are usually a kind of special stainless steel ball valves or carbon steel ball valves which are used in hydraulic industry, to control the fluid in the hydraulic systems.
As hydraulic ball valve is one sub category of the ball valves, so to explain what is hydraulic ball valve, we need to explain what is ball valve first.
What is ball valve?
Ball valves, as its name suggests, are stop valves that use a ball to stop or begin a stream of fluid. The ball (see in the below drawing) performs the exact same function as the disc in other types of valves. Since the valve handle is turned to open the valve, then the ball rotates into some stage where a part or all the hole through the ball is in line with the valve body enter port and export, permitting fluid to flow through the valve. After the ball has been rotated so the hole is perpendicular to the flow openings of the valve body, the flow of fluid ceases.