ISO 9001-2015 Company

Ball Valve

Ball Valve

API 6D, API6FA & ISO 17292

A Ball valve is a quarter-turn rotary motion valve that uses a ball-shaped disk to stop or start the flow. Ball valve resembles plug valve in many ways. When a port in the ball is in line, it allows flow whereas when you rotate the valve 90 degrees, solid part of the ball stop the flow. Major components of the ball valve are the body, spherical ball, steam, and seats. The ball valve can be metal seated or soft seated. A ball valve may be unidirectional, bidirectional, or multidirectional, depending on the number of valve ports and the number of valve seats. Same as multiport plug valve. In the image below, you can see the 3-way ball valve.

Most ball valves are of the quick-acting type, which requires a 90° turn of the valve handle to operate the valve. But in case large size valve which required considerable force to open or close the valve, the gear-operated actuator is used. With this arrangement, a small handwheel is enough to operate a fairly large valve. .
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Major components of the ball valve are the body, spherical ball, steam, and seats. The ball valve can be metal seated or soft seated. A ball valve may be unidirectional, bidirectional, or multidirectional, depending on the number of valve ports and the number of valve seats. Same as multiport plug valve. In the image below, you can see the 3-way ball valve.y.

Types of Ball Valve

In floating ball valve, the ball is held in the position by the compression of the two elastomeric seats against the ball. The ball is free to float inside the valve body. See the highlighted portion in the image and remember as you will see the difference when I will explain you about trunnion mounted ball valve.

Trunnion mounted ball valve is a solution to the problem of excessive torque required by floating ball valve in high-pressure service. A short shaft like an extension that called trunnion set in the body. You can see this in the image. In this design steam and ball work as a single unit. The ball is supported by two floating or spring-loaded seats that remain in constant contact with the ball. Trunnion ball design required a lower operating torque. Hence, reduces the size of the actuator and overall costs of the valve. This cost difference becomes an important factor when the pressure class and valve size increases.

In this design, a valve body is divided into two or three body parts. A ball, seat rings, stem, and other internals set inside the larger body part and held together with smaller part by bolting. For split body two pieces ball valve, refer floating ball valve image. Refer below image for split body three pieces ball

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