There are five general body styles of ball valves
: single body, three-piece body, split body, top entry, and welded. The difference is based on how the pieces of the valve-especially the casing that contains the ball itself-are manufactured and assembled. The valve operation is the same in each case.
In addition, there are different styles related to the bore of the ball mechanism itself.
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.