Ball Valve | What is a Ball Valve?
A Ball Valve is a type of rotary valve that uses a spherical element (ball-shaped) to control the flow of fluid. Most ball valves operate quickly with a 90-degree turn of the handle.
The main difference between ball valves and other valves is that in other valves, the role of opening and closing the flow path is performed by a blocking element (disc or gate), while in a ball valve, the fluid passage acts as the blocking element, controlling the flow of fluid by a 90-degree rotation.
In large ball valves, a significant force is required to open and close the blocking element; therefore, pneumatic actuators and gearboxes are used to operate large ball valves.
The fluid passing through these valves can be liquid, gas, corrosive, and acidic, depending on the diverse designs and materials used in the design of these valves, in a wide range of temperatures and pressures. These valves are also known as gas valves and ON/OFF Valves.
Ball valves are produced in various types based on their application type and location, featuring various variable and fixed components. The components of a simple ball valve are illustrated as follows.
There are different types of ball valves that are categorized based on their construction design, valve port size, actuator, and material as follows:
In addition to the above factors, when selecting and purchasing ball valves, consideration must be given to the type of connection, pressure and temperature range, and other specialized factors such as the size of the blocking element or ball disc, defined standards, etc.
Types of Ball Valves Based on Design
Welded Body
The parts and the body are welded together seamlessly; high resistance, no use of nuts and bolts, and no leakage in this type of ball valve make them a suitable and efficient option for transferring toxic fluids and oil underground or underwater. Repairing and cleaning integrated valves is very difficult.
Split Body
In this type of ball valve, the parts are connected in such a way that makes assembly and disassembly easy; hence, maintenance and servicing become easier.
Split ball valves themselves are categorized into single-piece, two-piece, and three-piece types. Other types of valves can also be made in single-piece, two-piece, and three-piece designs based on the requirements.
Top Entry
The spherical blocking element in this type of valve is connected to the seat from the top. Utilizing this configuration allows for service and replacement of the seat without removing the valve from the piping line.
This valve's configuration changes the seat position to a wedge or threaded seat outside the valve to improve leakage prevention.
End Entry
The blocking element is connected to the seat from the end or bottom of the pipe. Ball valves with bottom entry have threaded and flanged connections.
These valves can be used in various industries, including oil and gas extraction, water treatment, and slurry. Ball valves with bottom entry can range from small valves to large ones handling high fluid pressures.
Floating
In this model, the spherical blocking element is completely floating in the fluid and is only connected at the top to the seat; therefore, it is only used for low working pressures.
Trunnion
The blocking element is connected to the seat from two sides; these seats are sealed with rings and reinforced with several springs that apply significant force for effective sealing.
Thus, trunnion ball valves have a high capability to block flow and can be utilized in high working pressure applications. Trunnion ball valves require less torque compared to floating ball valves.
Three-Way
This type of ball valve can be used for regulating, mixing, or separating fluid flow. The blocking element or L-shaped tee has a shaped passage to establish flow in one direction or cut off flow from another inlet or outlet.
Double Block & Bleed
This valve uses two ball valves positioned sequentially for isolating or blocking flow in a section of the piping line for draining the isolated section.
Using double block and bleed ball valves saves installation time and costs compared to using multiple valves and reduces risks associated with transferring hazardous materials.
Ball Valves Based on Valve Port Size
Full-bore
The blocking element has thin walls; this means that the diameter of the opening is almost equal to the diameter of the pipeline, causing minimal pressure drop during fluid passage.
Additionally, this type of element is the best option for easy cleaning inside the valve.
Reduced bore
This model of the blocking element has a larger diameter than a full bore, making the valve diameter less than the pipeline diameter, resulting in a pressure drop during the flow of fluid.
Due to the reduced surface contact between the fluid and the body of the element, the flow velocity increases.
V-port
The blocking element has a V-shaped structure. The shape of this ball stabilizes the fluid's flow passing through it.
Cavity filler
The seat in this valve completely fills the space around the blocking element, minimizing the likelihood of fluid accumulating in this area.
These valves are used for hygienic applications and where the fluid is viscous.
Ball Valves Based on Material
Bronze
The applications of this material are diverse and can be combined with various alloys like aluminum. Bronze ball valves can be used in various industries, including seawater transfer lines, flanged connections, and more.
Stainless Steel
In environments where the fluid is corrosive or where the pressure and temperature of the fluid are high, stainless steel is used. Stainless steel comes in various types, with the most commonly used being type 304 (8/18) and type 316 (10/18). In high-temperature applications...
The applications of this material are diverse and can be combined with various alloys like aluminum. Bronze ball valves can be used in various industries, including seawater transfer lines, flanged connections, and more.
Stainless Steel
In environments where the fluid is corrosive or where the pressure and temperature of the fluid are high, stainless steel is used. Stainless steel comes in various types, with the most commonly used being type 304 (8/18) and type 316 (10/18). In high-temperature applications...
