Ball Valves
Exotica Valves™ manufactures a unique line of ball valves: Exotica BXK™. Ball valves are excellent quick shut-off, quarter-turn valves. They are probably the most common valve in the market. Easy to operate, ball valves are meant for isolation purposes though stand at a disadvantage to gate and especially globe valves where throttling is involved, as ball valves are not suited for throttling. The other drawback to ball valves is weight; as size and class increases, so does weight. Whereas a 12" 300# flanged gate valve could be expected to clock in at 600kg, a similar sized/class ball valve could weigh 50% more. The difference is even greater in the same class, but larger diameter: a 24" gate valve might weigh 2500kg compared to 5000kg for a ball valve.
Floating and trunnion guided ball valves
Torque is a major factor in ball valves, as the weight of the ball increases substantially when size increases. Whereas gate and globe valves cna be operated manually up to large sizes, ball valves quickly become unwieldy for manual operation. Gear operation or actuation quickly become necessary. Hence the trunnion mounted ball valve; trunnion ball valves are guided by a spring mechanism that allows the seats to float, often using line pressure. This reduces torque and allows for manual operation for some size/class combinations which, has the valve been a floating ball valve, would have required costly actuation.
Three-way ball valves
Three-way ball valves are used to guide the flow from a single point of entry to one or two downstream orifices, individually, or together. Three-way ball valves come in "T" port, where the flow is guided to both downstream orifices, "L" port where the flow is guided to one side or the other, but not both at the same time. "Y" port ball valves have two downstream orifices at 120º of the upstream orifice; pressure drop is less in "Y" ports compared to "T" ports.
Top entry and side entry ball valves
Valve maintenance is a major time and cost factor. End-entry ball valves need to come off the line to allow for access to the ball and seat areas; top-entry valves, however, allow for access through the bonnet area, by removing the stem in order to access the ball and seat from the top. Maintenance can be performed on-the-spot, which is useful for remotely located, or for valves that are otherwise difficult to transport.
Fully welded ball valves
Fully welded ball valves are aimed at heating plants, gas transport and storage. The valve's design reduces the risk of leakage around the body-bonnet joint. Uniformity across the body forging or casting is easier to achieve and the absense of flanges reduces the valve envelope and weight.
