Differentiate between Gate valve and Ball valve.

 Differentiate between Gate valve and Ball valve.

Ball valve

Gate valve

 The gate valve has a larger body, as compared to a ball valve of the same size and rating. 

 The gate valve body is vertically longer due to its disc that moves vertically in the body. Whereas in the case of a ball valve, the body is horizontally longer as the ball shape disc rotates in the body. So, now on you can easily identify these types of valves in the field. On this slide, I have shown a cross-section of both valves. 

The type of disc defines the types of valve in most cases.

 The valve disc is the component that stops or controls the flow through the valve. Gate valve disc is a vertical and flat circular plate whereas, in the case of a ball valve, it is a spherical metal ball. I want to highlight that both the gate valve and ball valve are used as an on-off valve. That means it can be either fully open or close. 

You cannot use these valves as a control valve as they are not designed for this function. If somebody is using these valves as a control valve then it is a wrong practice. 

The second difference is the way these valves are open. The gate valve is a linear motion valve whereas the ball valve is a rotary motion valve. 

The ball valve is a fast-acting valve as just a 90-degree turn can fully open or close the valve. In the case of the gate valve, the gate moves perpendicular to the flow of fluid, and it requires more time to open or close the valve. The stem of the gate valve is long as compared to the ball valve.

The ball is connected with the lever by a short stem. And in the case of the gate valve, 

The handwheel is connected with a disc through the long threaded stem. Both these valves can be operated by a motor. Small and medium-size balls are lever operated whereas large size ball valves require a gear mechanism with handwheel due to large torque requirements. 

On the other hand, gate valves are always operated through a handwheel with or without a gear mechanism depending on the size of the valve. 

The next difference is the material of the valve sheets. Gate valves are available in mainly metal sheet design whereas the sheet of the ball valves can be of metal or nonmetal depending on the temperature requirement. 

the multiport ball valve, ball valve offers multiple port options whereas gate valves are simple in design and always single port. 

That means only one inlet and one outlet. Cost-wise, the ball valve of the same size and rating will be costlier as compared to the gate valve. There are the main differences between the gate valve and the ball valve .

 Both gate and ball valves are the right choices for positive isolation. The ball valve offers a little superior shut off as compared to the gate valve due to soft sheet design. 

Choosing the correct valve for your service depends on many factors. Such as cost, fluid of the service, temperature,pressure, life cycle of the plant. 

See you soon. Goodbye, take care.