What is Ball Valve?

A ball valve is a mechanical device that guides and regulates the flow of various types of liquid through an opening in a ball. There is an opening in the middle of the ball. This opening is called a port. By turning the handle on the ball valve, manually open and close the port that controls the liquid flow pressure. Durability and perfect closing make ball valves superior to other types of valves. Let’s find more about the ball valve.

The following knowledge points are listed below:

• Basic description of ball valve

• How the ball valve works

• The common types of ball valve

1.  Basic description of ball valve

Ball valves exist in our daily lives, but they may not be noticed. For example, there are pipeline valves in our sewers. Our washing machines, dishwashers, gas stoves, outside faucets, refrigerators, etc. are all equipped with valves. Various types of industries use valves for production. These industries include electronics, power, automotive, printing, plastics, textiles, metals, medical, chemical and food. The industry that uses ball valves usually needs to support high pressures and temperatures in excess of 480 degrees. The ball valve is easy to operate and easy to maintain, and does not need to be disassembled from the pipeline.

The ball valve is made of steel, brass, iron, bronze or PVC, and its diameter ranges from 0.2 inches to 11.81 inches. More complex control systems require valves to regulate the flow through the pipeline, which requires actuators. The actuator controls the pneumatic or electric operation of the valve and maintains its proper position so that the flow of liquid is precisely changing the pressure and flow levels.

2. How the ball valve works

A ball valve is a shut-off valve that controls the flow of liquid or gas through a rotating ball with holes. By rotating the ball a quarter turn (90 degrees) around the axis, the medium can flow through or become blocked. They are characterized by a long service life, which provides reliable sealing even when the valve is not used for a long time. Therefore, they are more popular as gate valves than gate valves. In addition, they are more resistant to contaminated media than most other types of valves. In special versions, ball valves are also used as control valves. Compared with other types of control valves, this application is not common due to the relatively limited accuracy of the control flow. However, ball valves also have some advantages here. For example, this valve can still ensure a reliable seal, even in the presence of dirty media.

3.  The common types of ball valve

There are all kinds of ball valves, here are some of them.

(1) Standard (Thread)

The standard ball valve consists of a housing, a valve seat, a ball, and a lever for ball rotation. They include ball valves with two, three, and four ports, which can be internal or external threads, or a combination of these ports. Threaded valves are the most common valves. There are many types: ball valves suitable for specific media or applications, mini ball valves, angle ball valves, ISO-top ball valves, ball valves with integrated filters or exhaust points, etc. They have a wide range of options and a large working range of pressure and temperature.

(2) Hydraulic

The hydraulic ball valve is specially designed for hydraulic and heating systems, due to its higher working pressure rating and resistance of hydraulic and heating oil. These valves are either made of steel or stainless steel. In addition to these materials, the valve seat also makes the hydraulic valve suitable for high working pressures. The seats of these valves are made of polyoxymethylene (POM) and are suitable for high pressure and low temperature applications. The maximum working pressure of the hydraulic ball valve can reach more than 500bar, and the maximum temperature can reach 80℃.

(3) Flange

Flange ball valve has the characteristics of its connection mode. These ports are connected to the piping system through flanges, which are usually designed according to certain standards. Due to the usual full-bore design, these valves are able to provide high flow rates. When selecting a flange ball valve, in addition to the pressure rating, the compression level of the flange must also be checked, that is, the highest pressure that this connection type can withstand. These ball valves are designed with two, three or four ports, they can be used for specific media and have all the other functions that ISO-top and standard ball valves may have.

(4) vent

When it comes to their design, exhaust ball valves look almost the same as standard two-way ball valves. The main difference is that the air outlet vents the environment in the closed position. This is achieved by drilling a small hole in the ball and valve body. When the valve is closed, the hole is aligned with the air outlet, releasing the pressure. This is particularly useful in compressed air systems where decompression provides a safer working environment. Intuitively, these valves look like two-way ball valves, but in reality, they are 3/2 channels due to the ventilation of the small holes.

(5) Circuit function

This valve can have two, three or even four ports (2 way, 3 way or 4 way). Most ball valves are bidirectional and are manually operated by levers. When the valve opens, the lever is on the pipeline. In the closed position, the handle is perpendicular to the pipe. The manual ball valve can be closed quickly, so there is a danger of water hammer in the fast flowing medium. Some ball valves are equipped with transmission devices. The three-way valve has an l-shaped or t-shaped hole. Thereby various circuit functions can be realized, such as shunt or mixed flow. The following figure is a schematic diagram of the circuit function of the three-way ball valve.

I believe you have already know more about the ball valve after reading this article.