A ball valve is a member of quarter-turn valve in which a pivoted, perforated and hollow ball is used to control flow through it. When the ball’s hole is lying in line with the flow it is opened and when it is pivoted to 90-degrees by the valve handle then it is closed. When the handle is parallel to the flow axis flow it is open, and closed when it is perpendicular to the flow axis, this is indicating visual confirmation of the valve’s position.
These ball valves perform usually well after numerous cycle, durable in nature, reliable and get closed securely even after long phase of disuse. These qualities make them an excellent choice for control shut off for various applications, sometimes they are preferred over globe and gate valves but have less fine control in case of throttling applications.
These ball valves lend versatility for industrial use along with easy operation and repair as it supports pressure up to 1000 bar and temperature up to 752 degree F depending on material use and designs. The size of these valves has a range from 0.2 to 48 inches. Valve body is made metal with ceramic, plastic and only metal while floating body are often chrome plated for durability. The main disadvantage of this ball is water trapping in center cavity when in closed position. These sides can crack in freezing condition due to expansion of ice formation. Another option is freeze tolerant ball valve for cold climate. This type of ball valve integrates a freeze plug in side in context of freezing up the freeze plug ruptures and making it easy to repair. In the new freeze plug a screw is replaced instead of the whole valve.
Ball Valves style is categorized into five general bodies. It includes three piece bodies, single body top entry, split body and welded. The difference is based on casing of the ball that are assembled and manufactured. The operation of ball is same in each case.
In addition, various styles are related to the bore of mechanism of ball itself.
Ball valves that comes in single, two and three pieces designs goes up to 2 inchs. One piece ball valve is reduced to bore that is generally thrown away and are relatively inexpensive. Two piece Ball valve have reduced bore and they can be repairable or throw away. The three piece allows central part of valve containing stem, ball and seats that are removed from pipeline. These facilities are efficient in cleaning of sediment deposition, gland packing, replacement of seats and cleaning of ball is done without removal of pipes from valve body. The three piece valve design concept is repairable in nature.
- Valve stopper is ball shaped.
- For use as an on/off valve (not suitable as a control valve).
- Little resistance to flow when fully open (allows smooth flow).
- Optimal for automated operation with a 90 degrees operating angle.
- Advanced technology is required to manufacture ball.