Ball Valves

TYPE of Valves : 2 way, 3 way, 4 way, 5 way, 1 piece, 2 piece, 3 piece Design.
Quarter turn, Half turn, Full turn i.e. L Port 900, T Port ( full turn )

A Ball Valve Is A Valve With A Spherical Disc, The Part Of The Valve Which Controls The Flow Through It. The Sphere Has A Hole, Or Port, Through The Middle So That When The Port Is In Line With Both Ends Of The Valve, Flow Will Occur. When The Valve Is Closed, The Hole Is Perpendicular To The Ends Of The Valve, And Flow Is Blocked. The Handle Or Lever Will Be Inline With The Port Position Letting You "See" The Valve's Position. The Ball Valve, Along With The Butterfly Valve And Plug Valve, Are Part Of The Family Of Quarter Turn Valves.

Duplex ball valve
In addition, there are different styles related to the bore of the ball mechanism itself:
A full port or more commonly known full bore ball valve has an over-sized ball so that the hole in the ball is the same size as the pipeline resulting in lower friction loss. Flow is unrestricted but the valve is larger and more expensive so this is only used where free flow is required, for example in pipelines which require pigging.
In reduced port or more commonly known reduced bore ball valves, flow through the valve is one pipe size smaller than the valve's pipe size resulting in flow area being smaller than pipe. As the flow discharge remains constant and is equal to area of flow (A) times velocity (V), A1V1 = A2V2 the velocity increases with reduced area of flow
Three-way and four-way ball valves
Schematic 3 way ball valve: L-shaped ball right, T-shaped left
Three-way ball valves have an L- or T-shaped hole through the middle. The different combinations of flow are shown in the figure. It is easy to see that a T valve can connect any pair of ports, or all three, together, but the 45 degree position which might disconnect all three leaves no margin for error. The L valve can connect the center port to either side port, or disconnect all three, but it cannot connect the side ports together.
Multi-port ball valves with 4 ways, or more, are also commercially available, the inlet way often being orthogonal to the plane of the outlets. For special applications, such as driving air-powered motors from forward to reverse, the operation is performed by rotating a single lever four-way valve. The 4-way ball valve has two L-shaped ports in the ball that do not interconnect, sometimes referred to as an "×" port.
Ball valves in sizes up to 2 inch generally come in single piece, two or three piece designs. One piece ball valves are almost always reduced bore, are relatively inexpensive and generally are throw-away. Two piece ball valves are generally slightly reduced (or standard) bore, they can be either throw-away or repairable. The 3 piece design allows for the center part of the valve containing the ball, stem & seats to be easily removed from the pipeline. This facilitates efficient cleaning of deposited sediments, replacement of seats and gland packings, polishing out of small scratches on the ball, all this without removing the pipes from the valve body. The design concept of a three piece valve is for it to be repairable.....