Login

Your Name:(required)

Your Password:(required)

Join Us

Your Name:(required)

Your Email:(required)

Your Message :

Your Position: Home - Hardware - What is ball valve? How does a ball valve work? Tell You Ball Valve Basics!

What is ball valve? How does a ball valve work? Tell You Ball Valve Basics!

Author: Adelaide

Jul. 20, 2021

Hardware



What is ball valve?


Before learning about ball valves, I wonder if you know that ball valves and globe valves are often be put into compression together, but we won't go into much detail about their differences here. Simply saying, a ball valve is a quarter-turn globe valve that controls the flow of fluid by means of a rotating ball. 


The spherical, rotating ball consists of a straight bore through which it passes. When this hole is in the same direction as the flow of water, the pipe is open and allows the passage of fluid. Depending on the operating conditions, the ball valve can be equipped with different actuators to form a variety of different control methods, such as electric ball valves, pneumatic ball valves, hydraulic ball valves, etc. 


Components of a ball valve


1. Valve housing


The valve housing protects the internal components and has connection points at the inlet/outlet. Brass, stainless steel and PVC are the most commonly used housing materials. Valve bodies can be assembled in one-piece, two-piece or three-piece designs. 


Ball Valve Types Based on Valve Housing


One-piece

This is the least expensive valve option. In the one-piece design, the two parts that enclose the ball are joined by pressing and welding, so they cannot be opened for maintenance. Therefore, they are used in less demanding applications.


Two-piece type

Two-piece valves have threaded connections for the parts. Therefore, they can be disassembled for maintenance purposes. However, the valves need to be completely removed from the piping to separate the parts for repair and maintenance.


Three-piece type

The parts of a three-piece valve are generally clamped together by bolted connections. The valve does not need to be completely removed from the pipeline for maintenance. This is the most expensive valve design option, but provides the best solution for sanitary applications. 


2. Ball design


Swivel ball design

Swivel balls with holes to allow or stop the passage of media through the pipe. They are usually made of stainless steel, PVC, chrome-plated steel or chrome-plated brass. Depending on the design and support of the ball, they can be classified as floating or trunnion type.


Floating ball design

The seat provides support for the ball to accommodate different temperature applications. This is the most common ball design.


Trunnion ball design

The ball is supported at the bottom and top to reduce the load on the seat. This design is used in high quality valves and provides a reliable seal in both high and low pressure applications.


Bore ball design

These valves have a bore size smaller than the diameter of the inlet/outlet connection. As a result, there are frictional losses in the system. However, these losses remain small compared to other valves. Most ball valves have a reduced bore design.


Full bore ball design

These valves have the same bore size as the diameter of the pipe. Therefore, there are no additional frictional losses and they are also easy to clean. However, they are slightly more expensive due to their larger diameter and are not needed in most applications for which a standard reduced bore is sufficient.


V-Bore ball design

The bore of these valves has a V-shaped profile. As a result, precise flow rates can be achieved by rotating the ball. By optimizing the V-bore profile, a linear flow rate can be achieved.


3.valve stem


The opening or closing of the valve is provided by the valve stem. This is also the link between the ball disc and the lever, handle or actuator. The stem is the person who rotates the ball disc to open or close it. 


4. Valve bonnet


The bonnet is a covering for the valve orifice. It acts as a second barrier to pressure. The bonnet is what holds all the internal parts together after they have been inserted inside the valve body. The bonnet is usually made of the same material as the valve body and can be either forged or cast. 


5. Valve actuator


Actuators are the devices that create the rotation required by the ball valve to open the disc. Typically, these have a power source. Some actuators can be controlled remotely so that the valve can still work even if these actuators are located in remote or hard to reach areas. It can be used as handwheels for manually operating ball valves. Some other types of actuators include solenoid types, pneumatic types, hydraulic types, and gears. 


How does a ball valve work?


The work principle of all types of ball valves is, broadly speaking, as the following:


Whether manually operated or actuator operated, the thrust turns the handle a quarter turn to open the valve. This force is transferred to the stem, which pushes the ball disc open. The disc rotates and the ball bore allows the flow of media. At this point, the lever is in a vertical position and the ball orifice is parallel to the media flow. A handle stop at the connection of the stem and the bonnet allows only a quarter turn. To close the valve, the lever is moved backward a quarter turn. The stem movement causes the ball disc to rotate in the opposite direction, blocking the flow of media. The lever is in the parallel position, while the port is vertical. 











Conclusion


Ball valves are known for their durability, simplicity, and excellent sealing performance. They provide excellent shutoff even after years of use. This makes ball valves the best choice for globe valves. They also provide better resistance to contaminated media than other valves. In addition, ball valves are not often used as control valves because their flow control is less precise. However, they are cost effective and can be used in applications that do not require precise flow control accuracy. 

561

0

0

Comments

0/2000

All Comments (0)

Related Articles

Guest Posts

If you are interested in sending in a Guest Blogger Submission,welcome to write for us!

Your Name:(required)

Your Email:(required)

Subject:

Your Message:(required)