Ball valves, as per their name, have a hollowed ball inside and operates through a quarter turn operation. Usually operated using a lever, the valve is open when the hole in the ball is in line with the flow and closed when perpendicular. The handle will be inline with the valve body when the hole is aligned with the flow and is perpendicular to it when closed. This allows for easy visual confirmation of the valve's status.
Ball Valves are durable and perform well after many cycles of operation. The nature of the design allows for secure closing even after long periods of disuse. These qualities make Ball Valves an excellent choice for shutoff and isolation applications, however, they can also quite easily be closed quickly and therefore pose a danger of inducing water hammer in a system.
The applications for Ball Valves are wide-reaching however, care must be taken to understand the internal components. Typically the seat can restrict usage with specific mediums and fluids.
Types Of Ball Valve
Ball Valves come with a few variations. Typically these surround the design of the ball and the body of the valve. Variations in the balls include; Full Bore, Reduced Bore, V Port and Trunnion. Furthermore, Ball Valves offer the ability to be multidirectional, known as Multiport Ball Valves.
Full Bore Ball Valves have a larger ball so that the internal diameter of the hole matches that of the pipeline resulting in lower friction loss. Consequently, the Valve itself is larger.
Reduced Bore Ball Valves has a smaller ball but also a smaller internal diameter. Flow through this type of Ball Valve is therefore slightly restricted.
V Port Ball Valves have either a 'V' shaped ball or a 'V' shaped seat. This gives more control to the operator when opening and closing the valve. When the valve is closed and the operator opens the valves, the small end of the 'V' is opened first allowing for a linear increase in the flow during the opening process.
A Trunnion Ball Valve anchors the ball at the top and the bottom, giving a more secure fixture. This type of Ball Valve is typically used with high pressure applications and larger sizes.
Flowflex offer a range of Ball Valves. You can see the full range here.
Ball Valves should not be used to control or regulate flow as they do not provide any accuracy in performing this role.