Difference Between Gate Valve and Globe Valve
Difference Between Gate Valve and Globe Valve
Gate valves and globe valves are two of the most common valves used in industrial applications. Both contribute greatly to any industrial services. They may look alike but these valves function differently. In this article, you will know what makes the gate and globe individually unique as well as the major differences between the two valves.
Gate valves are linear valves belonging to the shutoff valve family. Characterized by its wedge-like disc, the gate valve is commonly used for isolating media because of can tightly seal off media. This kind of valve can be used in applications where tight sealing is required. A special kind of gate valve, knife gate valve, is used in thicker and more viscous media.
Gate valves provide little pressure drops since no obstruction comes in the way of media flow. The gate operates by the gate disc moving upwards to open the valve. It closes by moving the disc downwards to meet with the seats. The disc of the gate valve can be formed like a wedge, knife or parallel.
While it does have some throttling capacity, the gate valve is not used to regulate the flow of media. Its disc is thin so the vibration from the media causes this thin disc to misalign from its seat. This condition causes damage and shortens its service life. To lengthen the valve life, the gate valve should fully open or fully close when in use.
The globe valve is also a member of the linear motion valve family. Its functions include stopping and starting of media as well as regulate the flow of media. Because of its design, the globe valve provides a tight seal with fewer chances of leakage.
The globe valve is aptly named as such because of its traditional body design similar to that of the globe. But as one gate valve China manufacturer would tell you, however, modern globe valves may adapt to other body shapes. A plug-like disc allows or prohibits the flow of media.
The seats of the gate valve are parallel to the flow of the media so there is less seat erosion when the valve is on. This also makes the globe valve a great throttling valve. The downside is, there is a high-pressure drop because of its design.
If you look at the image above, you’d notice that the valve forces the media to change its flow direction exactly inside the valve. Additionally, the media flow inside the valve depends on the space between the seat and the disc. The farther these are, the more fluid comes in.
Globe valves highly suitable for applications where safety and leaks are the main concerns. These valves are often in top-entry design, meaning, access to the internal components of the valve is from the top.
Gate Valve vs. Globe Valve
There is always a comparison between the gate valve and the globe valve. Members of the linear valve family, you’d find these two in tandem in pipe systems. How would you use these two? Look at the differences between the two below:
Structure
One of the main differences between the gate valve and the globe valve is how these look. The gate valve construction is much simpler. Much of its internal components are located on the top part of the valve body. When it is turned on, its body becomes hollow. That’s why there is a little pressure drop. The gate valve may have a rising or a non-rising stem.
On the contrary, many globe valve parts are inside the cavity itself. Since its primary purpose is to throttle and provide positive shut-off, the design allows obstructions that aid the globe valve in this purpose. The design also permits changes in flow direction and rate that contributes to a high-pressure drop. The globe has a rising stem.
Applications
The gate valve is suitable for applications where low-pressure drops are of utmost importance. It’s a multidirectional valve. The globe is best used in applications where massive changes in pressure are not an issue. This valve is unidirectional.
Function
The gate valve is not designed for flow control; it is for isolation of media. The gate valve cannot handle the strength of the media flowing in a partially opened position. On the other hand, the globe valve is more of a control valve.
How They Work
In the gate valve working mechanism, the disc lodges between the seats. Its movement is at the right angle in relation to the media flow. It provides either full flow or no flow at all. If you open the valve, the flow space is as big as the valve cavity with little extra where the stem and the seats are located as you’d notice in the first image.
Globe Valve vs Gate Valve
Figure 1: Globe valve (left) and gate valve (right)
Despite their similarities at first inspection, globe and gate valves have significant differences that make each suitable for their applications. When choosing between these two valves for an application, understanding the application's pressure, sealing, and flow requirements can ensure the correct valve is selected. This article discusses the differences between globe and gate valves to allow an educated decision before choosing between the two valves.
Table of contents
Globe valve vs gate valve comparison
Globe valves and gate valves are multi-turn, linear motion valves, meaning both valves require multiple turns to open or close. The closing mechanism moves up and down in a straight line to turn open or close the valve. At this point, similarities between the valves begin to diminish.
The globe valve differs from most valves because its name derives from its body shape (rounded) rather than its disc, which is the gate valve's convention. Its disc moves up and down to allow or block the flow, similar to a gate.
Read more on globe valves and gate valves to get a comprehensive understanding of both.
Flow properties
As seen in Figure 2, a gate valve is a straight-through, bi-directional valve, meaning its design permits flow directly through it in both directions. The only change to the flow occurs when the gate valve is closed, and the flow stops.
Figure 2: A gate valve flow properties when it is closed (left) and open (right).
A globe valve, on the other hand, has more turns for the flow path. As seen in Figure 3, the flow can take a z-shaped path (T- or Z-valve), an oblique path (Y-valve), or a 90° turn path (angle valve).
Because a globe valve diverts flow in a specific way, it has an inlet and an outlet port. Typically, an arrow on the outside of the valve's body will indicate the valve's flow direction. Also, the flow diversion causes a significant pressure drop through the globe valve. In contrast, a gate valve's pressure drop is nearly non-existent.
Figure 3: Globe valves' flow paths: T- or Z-valve (left), angle valve (center), and Y-valve (right)
Valve functions
Both gate valves and globe valves can operate as on/off valves. A gate valve is not meant to bused to throttle flow, but a globe valve can. Flow diverts within the globe valve and becomes parallel to the valve seat. This design makes globe valves efficient flow throttlers. Globe valves become unsuitable for throttling flow at larger diameters (above DN 150). Gate and globe valves can be operated mechanically, pneumatically, or electrically.
Note: With other factors equal, Y-valves are the least efficient at throttling flow because the valve seat is not parallel to the flow direction. However, this also means that Y-valves have the smallest pressure drop.
Visual differences
At a quick glance, gate valves and globe valves are not easy to tell apart. The following traits are what to look for to tell the difference:
Body: Gate valves usually have a rectangular or wedge-shaped body. Whereas the body of a globe valve is rounder, especially at its bottom.
Max height: Gate valves usually are higher when opened than globe valves.
Flow direction indicator: Gate valves are bi-directional, whereas globe valves are unidirectional. A marker on the valve, such as an arrow, indicates the flow direction and that it's a globe valve.
Advantages and disadvantages chart
Globe and gate valves may have similar or different materials for their housing and seals. Read our chemical resistance guide to learn more about the advantages and disadvantages of the various materials. See the following chart to learn about more advantages and disadvantages.
Globe valve Gate valve Application Used for flow regulation (e.g., cooling water systems and fuel oil systems) More suitable for slurry due to less space in the valve's body for sediment to get stuck and build up Flow control Can be used or on/off control and can throttle flow Can be used for on/off control and cannot regulate the flow Flow capacity Lower Higher Flow direction Unidirectional Bi-directional Flow restriction/pressure drop Flow diversion within the valve's body creates significant pressure drop Full-bore valve, meaning there is no reduction to flow and pressure drop is insignificant Power requirement Needs a large amount of force or an actuator to close under high pressure Needs less power to close under high pressure Operating conditions Can operate at higher temperatures Can operate at higher pressures Cost More expensive than a gate valve due to its complicated structure Cheaper Leakage More effective sealing because force is applied to the disc when closed Good sealing properties Installation space Takes up less vertical space, but requires more horizontal space If a rising-stem style, needs more vertical space, but less horizontal space Weight Heavier Lighter Ports Can have a 3-port configuration for straight-through flow Two ports
Table 1: Globe valve and gate valve advantages and disadvantages chart
Selecting between globe valves and gate valves
Gate valves and globe valves are both excellent shut-off valves. However, when choosing between them, neither valve will outperform the other in every single application. Consider the following factors:
Flow control: Select a globe valve if an application requires flow modulation.
Flow capacity: Choose a gate valve if an application demands high flow.
Flow direction: Choose a gate valve if an application requires bi-directional flow.
Pressure drop: Select a gate valve if a minimal pressure drop is necessary.
Sealing: If an application demands excellent sealing, select a globe valve.
Contaminated media: Choose a gate valve if an application has slurry or other contaminated media.
The above variables are typically the most important when selecting a shut-off valve. Refer to Table 1 for further information.
Example applications
Globe valves
Cooling water systems: Globe valves operate in cooling water systems by controlling the water flow to maintain a desired temperature.
Chemical injection systems: Globe valves work well in industrial systems that need control over chemicals into reaction vessels or process streams.
Gate valves
Bulk material handling systems: Heavy-duty processes (e.g., mining, agriculture, and construction) use gate valves to control the flow of bulk materials such as grains, coal, and aggregate.
Water distribution systems: Many components of a water distribution system do not require precise flow control. Therefore, gate valves are suitable because they either block or allow flow.
FAQs
Which is better? A gate valve or a globe valve?
Globe valves have better sealing than gate valves and last longer. However, gate valves have significantly lower pressure drop.
What is the advantage of gate valves over globe valves?
One significant advantage of gate valves over globe valves is that they require significantly less power to close since they close perpendicular to flow rather than parallel as globe valves do.
Difference Between Gate Valve and Globe Valve
In this article from Linquip, we want to talk about the difference between gate valve and globe valve. These two valves are among popular valves that are used for many industrial and residential applications. They provide many useful services that differ from each other. While similar in appearance, they function differently. By comparing these two, you will be able to know these differences better.
Globe Valve vs. Gate Valve
If you want to know the difference between gate valve and globe valve, you should compare every little aspect of these two; from application to structure and function. Now, we’ll dive into comparing these two.
Application
Globe valves are used for applications where huge changes in pressure are not important. This is while gate valves are usually used where even low-pressure drops are very important. Another difference in the application between these two valves is that gate valves are multi-directional, while globe valves are unidirectional.
Structure
Another difference between gate valve and globe valve is in their structure. This is among the main differences between these two. While the gate valve has a simple construction, the globe valve is much more complex. Many of the internal components of a gate valve are located on the top of the body. They may have a rising or non-rising stem. When the valve is turned on, the body becomes hollow. This body structure is the reason that the pressure drop is low.
On the other hand, globe valves have a complex structure since their internal parts are inside the cavity. They have a rising stem. The main purpose of a globe valve is to provide positive shut-off and throttle. Globe valves can also change the flow direction and flow rate which causes high pressure drops.
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Function
Another difference between gate valve and globe valve is in their function. As mentioned above, globe valves are capable of changing flow direction and flow rate. This is while the gate valve is not capable of controlling the flow. Gate valves are designed for media isolation purposes. The design of the gate valve is in a way that can’t handle the pressure of the media flowing in a semi-open position. Globe valves are better for this task and are more known to be operating as control valves.
Working Mechanism
The other difference between gate valve and globe valve is in their working mechanism. Gate valves provide full flow or full shut-off. The disc in the gate valve lodges between the seats. The movement of the disc is at the right angle in relation to the flow of the media. When the valve is in the open position, the cavity is almost empty, and the flow space is as big as this space. A little extra space is left for the stem and the seats.
On the other hand, the movement of the globe valve disc is parallel to the flow of the media. The disc only moves a bit from the seat which means it provides a full flow. Globe valve has been designed in a way that provides tight shut-off and throttling.
Price
Gate valves are usually cheaper than globe valves of the same size due to their easy construction.
The overall difference between gate valve and globe valve
Gate valves are linear valves and belong to the family of the shut-off valves. They have a wedge-like disc. Because of their ability to provide tight seal-off, they are usually used for isolating media. When there are thicker media involved, a special kind of gate valve known as a knife gate valve is used to provide tight sealing. The gate valve disc can be formed like a knife, wedge, or parallel. As mentioned above, they provide little pressure drop because the media flow comes across with no obstruction.
When the disc moves upward, the valve is in the open position and starts to operate. When the disc moves downward and reaches the seats, it is in the closed position and the flow stops.
Gate valves are usually not used for regulating the media flow. Because of its thin disc, the vibration of the media movement causes the disc to misalign from the seat which causes damage and constant needs of services.
Globe valves, as well, are among the linear motion valve family. They are used for stopping and starting the media flow. They can also regulate the media flow as well. They provide tight shut-off and a low chance of leakage. When safety and leaks are among the main concerns, globe valves should be your go-to.
Globe valve seats are parallel to the media flow and because of this movement, there is less seat erosion in the open position. They are also considered great throttling valves. As mentioned above, due to their design, they have high pressure drop which is considered as a down point.
Quick Comparison:
Globe valves are usually used for flow regulation, while gate valves are often used for on-off control.
Gate valves are cheaper than globe valves.
Gate valves have little pressure drop across the valve and provide little resistance to the media flow in the open position. Globe valves, on the other hand, provide substantial resistance to the flow of the fluid and have high pressure drops.
Gate valves have a simple design, whereas globe valves have a complex design.
Gate valves are unidirectional while glove valves are multi-directional.
Gate valves provide little fluid trapping in the line, but globe valves trap a larger amount because of their flow direction.
That was all there is to know about the difference between gate valve and globe valve. Although these two valves look somehow the same, we saw a huge difference in the function between the two. What do you think about these two? Which one do you think works best? Comment below and share your thoughts with us. Also don’t forget to signup on Linquip to ask our experts for help. We will answer all your questions in the blink of an eye.
FAQs about Difference Between Gate Valve and Globe Valve
What is the use of globe valve and gate valve?
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Globe valves are frequently employed in plant plumbing and get their name from the shape of their exterior. Both manual and automated operation are acceptable for them. Globe valves, in contrast to gate valves, may be used to control flow or pressures as well as completely stop flow.
Why should a globe valve not be used for isolation purposes?
Due to wear on the plug or seat or because of their design, globe valves and butterfly valves might not be able to close tightly enough to offer adequate isolation.
What is the main disadvantage of the gate valve?
High friction and erosion: As gate valves are utilized over time, the sealing faces may erode or sustain other damage. High friction between the contact sealing faces during valve opening and closing results in erosion damage or scratches to these sealing surfaces.
Which is better globe or gate valve?
Even when the valve is fully open, they have a considerable pressure drop and provide an additional barrier to fluid flow. Globe valves often last longer and have a better seal than gate valves. They cost more than gate valves of comparable size, but in circumstances where throttling is required, they could be worth the extra cost.
Does globe valve reduce water pressure?
In contrast to gate valves, globe valves do not let fluids pass through completely. Instead, fluid passes through a globe valve in a non-linear manner, reducing the pressure of the fluid in the line as it does so. The majority of globe valves are designed to open at pressures lower than 300 psi.
Does gate valve reduce water pressure?
The water pressure gradually drops as the gate opens and shuts, preventing these pressure waves. Gate valves must only be used to start or stop the flow of fluids, just as ball valves.
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