Difference between Gate Valves and Ball Valves
One of the most important components of a functional plumbing system is the valves it contains. Valves allow for the start and stop of the flow of liquid, and they need to work well to prevent leaks and unwanted flow. While there are a number of valve types on the market, two of the most common are the ball valve and the gate valve. Here's what you need to know about these two valve types.
What Is a Gate Valve?
A gate valve gets its name from the internal mechanism that enables the flow of water. This mechanism looks like a tiny gate that moves up and down on a stem, which is connected to the handle. The handle is a screw handle that moves the gate up and down, opening and closing the valve as needed. They are best used in on/off applications where the valve is used infrequently. They are sometimes found in home plumbing systems, though ball valves are becoming more popular in this area. They are also commonly found in the oil and gas industry, pharmaceuticals, manufacturing, automotive, and marine applications. They can be used in high pressure and high temperature environments, so are often found in manufacturing.
Gate valves have one major advantage over ball valves. Because the opening and closing mechanism is slow, they can't cause a water hammer. For this reason, some municipalities require the valve nearest to the water meter to be a gate valve.
However, gate valves have disadvantages as well. The screw mechanism that opens and closes the valve can easily fall victim to corrosion. Once corroded, the valve won't work properly. Gate valves should be used in fully open or fully closed positions, but it is possible on some models for the valve to be stuck partially open or partially closed. This causes vibration of the gate, which can damage the valve. Gate valves can be hard to operate by those with disabilities, and they don't provide a visual clue to the "on" or "off" position.
Types of Gate Valves
While the basic function of a gate valve is the same regardless of the type, you will find a number of valve types on the market. Your application will determine which type you need.
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