Gate Valve vs Ball Valve - How They Work

Gate valves and ball valves are the most commonly used flow control valves in the market. They are generally used to control the flow of liquid and gases. Although they are used in similar settings, there are a few important differences between these two valves. We discuss the differences between gate and ball valves and how to choose between them.

Operation differences

A ball valve uses a rotary ball with a bore and a stem . When the handle attached to the stem is turned, it rotates the ball to open or close the valve. This valve is also called a quarter turn valve because the handle only needs a 90° turn (quarter turn) to allow or block the flow of the media. The valve is open when the handle is parallel to the pipe and it is closed when the handle is perpendicular to the pipe.

A gate valve uses a gate to control the flow of the media. A gate is a solid disk structure that is connected to the stem, as seen in Figure 2. The gate is lifted to open the valve and is returned down to its original position to close the valve. The valve is accompanied by a bonnet which when rotated controls the position of the gate. This valve is also called a multi turn valve because it takes more than a 360° turn to fully open or close the valve.

If the flow is abruptly stopped by rapidly shutting off the valve, pressure builds up due to the momentum of the moving medium and this causes a short pressure surge. The pressure surge causes a noise which sounds like the pipes were struck by a hammer. A powerful water hammer can cause a rupture or leak in the system.

Both ball valves and gate valves are commonly used in residential and industrial applications.

Gate valves are generally found in older plumbing systems and in applications where frequent shut off is not required. Large water supply lines use gate valves due to their straight flow path and less flow restrictions. Ball valves are increasingly used in new plumbing systems with frequent shut off requirements.

Gate valves are used for application with slurries and viscous media because they are easier to clean and maintain. Ball valves are not desirable because they are difficult to clean, and the slurry particles may damage the rotary ball.

Gate valves are used in power plants, mining and water treatment applications which are high temperature and high-pressure environments.

Ball valves are commonly used in fire protection systems and marine applications. They are best not used in food, beverage and pharmaceutical applications as ball valves are difficult to clean and may cause contamination.

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