Ball Valves
A Ball valve houses a sphere, or ball, with a central port that allows or restricts flow. As the valve handle is turned and the ball is rotated, the valve opens and medium passes through. In the fully open position, the valve provides unrestricted flow. When closed, flow is completely restricted.
Ball valves require a one-quarter turn to go from the fully open to fully closed. This quick opening and closing makes the Ball valve a valuable tool where quickly isolating sections of the line is important. While Ball valves are generally used in the fully open or fully closed positions, the handle can be turned to semi-opened or semi-closed to control flow.
The most common type is the Full Port Ball Valve. The sphere is oversized, with the port in the sphere being equal in size to the inside diameter of the pipe or tube to which the valve is mounted. Standard Port Ball Valves have a smaller sphere with a correspondingly smaller port. Flow through the port is thus slightly restricted in the fully open position.
Ball valves are available in one-piece, two-piece, or three-piece construction.
The three-piece Ball valve is made up of three pieces: two end caps and one body. The end caps are where the connection to the pipe or tube is made, and are either butt weld, flanged, grooved, threaded, socket weld or tri-clamp (tri-clover).
A three-piece construction is ideal for processes that put heavy demands on the valve. To replace seats and seals, the three-piece valve can be easily disassembled, serviced and reassembled. Additionally, three-piece Ball valves allow for elastomers to be changed to for different process temperatures, pressures and flows.
Two-piece Ball valves consist of two pieces, with the connection between them being either threaded or a bolt-and-flange assembly. While they are also maintenance friendly, unlike the three-piece valve, the body of the two-piece valve cannot be removed without disturbing the end caps. Nonetheless, they are a good option for systems where a valve may require flexibility and maintenance.
One-piece Ball valves are the least expensive, and generally are not repaired if they fail. Their one-piece construction makes them a great single use option.
Ball valves have many uses. They’re the most used fluid shutoff valve in upstream oil and gas production facilities, but are also found in the food & beverage and pharmaceutical industries, among many others. Ball valves are not recommended for flow control due to the potential for excessive wear.
James Duva, Inc. offers a full line of Ball Valves, in many material grades and pressure classes, with or without actuation, built by manufacturers you trust. Whatever your specific needs, call us today.