What is a ball valve?
Ball valves are used in almost all industrial processes, including water and wastewater treatment, mining, power generation, oil, gas and petroleum processing, food production, manufacturing. chemicals and plastics and many other fields.
Ball valve is composed of a ball with a hole and rotates to control the flow through it. Ball valves are often used in factories with ball valves, crank ball valves, pneumatic ball valves or electrically controlled ball valves.
Structure of ball valve
The internal structure of the ball valve consists of a ball with a hole for the passage of the medium. The ball is held tightly between two sealing rings (seat). The lever / handwheel is installed at the top of the valve seat. When turning the lever / handwheel at a 90 degree angle, the valve will be in the closed position or the open position. Therefore, ball valves are also quick-open type. Because of their shape, ball valves are slippery and easier to operate than plug valves. So reducing friction between the ball and the sealing rings during operation therefore they do not require lubrication. The lever of the ball valve is similar to the stopper valve which will lie parallel to the flow when the valve is in the open position. When the handle is perpendicular to the pipe, it is in the closed position. This makes it easy to locate the operating status of the valve.
Materials of ball valve construction
The valve body can have many types of materials, one of which is:
And many more ...
There are many types of materials for the production of SEAT valves (ball bearings and valve body). Each material has its own application and is suitable for chemical compatibility, pressure and temperature. Some frequently used materials are:
Reinforced Teflon (RTFE)
Kel F (PCTFE)
Virgin Teflon (TFE)
UHMW Polyethylene (UHMWPE)
Types of ball valves
Ball valves are divided into several categories based on the valve's structure, or on manual or electrical operation (actuators).
A / Based on the valve body structure
There are 5 common types of ball valves: single body, three-piece body, split body, top entry, and welded. The difference is based on how the parts of the valve - especially the ball bearing housing - are manufactured and assembled. The valve operation is the same in each case.
Reduced port or reduced bore.
B / Based on the transmission
Pneumatic ball valve: Part of the ball valve comes with a compression action that helps the valve change its state from closed to open and vice versa.
Electrically controlled ball valve: The accompanying ball valve is an electric actuator that helps the valve change its state from closed to open and vice versa.
Reference: learn electric ball valve
Principle of operation of the ball valve
To learn more about how ball valves work, please watch the video below:
Pros and Cons of Ball Valves
Ball valve is durable, works well after many cycles, and reliably, opens / closes easily, safely even after long periods of non use. It is these factors that make them a preferred choice for open / close and control applications where they are often preferred for use over globe valves or swing valves. However, ball valves lack good control in flow control applications. Together with its simple construction, flexible operation and repair, ball valves are widely used in industry, supporting pressure up to 1000 bar and temperature up to 752 ° F (400 ° C). Ball valve sizes usually range from DN8 to DN2000 ..
Although ball valves are used in many places to replace globe and gate valves, ball valves do not regulate the desired flow as a damper.
The ball valve is a series of quick opening / closing valves, so the friction pressure between the ball body and sealing gasket is enormous. Therefore, these parts are often prone to damage during use.
Ball valves cannot be used in dirty or thick environments. In the case of thick media, you can switch to a gate or butterfly valve.
Famous Brand Ball Valves In The Market
Like other industrial valves, ball valves are also manufactured in many countries around the world. There are countries with the world's leading developed industries such as Germany, USA and Japan. Or if the product is just fine, and the desire is cheap, you can choose from Taiwan, China ...
Currently, in the industrial valve market in Vietnam. You can select brands of industrial ball valves such as:
KSB Armaturen / Germany.
Metso / Germany.
Zetkama / Poland.
JOEUN / Korea.
TUNGLUNG / Taiwan.
NVS / Taiwan.
With the brand of ball valves, there are different strengths and weaknesses. Please consider carefully before choosing to buy!
Above is an article sharing knowledge about ball valves in the series of articles about industrial valves in italy. Although we have tried to edit and complete it in the most complete and detailed way.
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