The valve core of gate valve and ball vave

Ball Valve

The valve core of the ball valve is a ball. Because of its fixed ball structure, the valve is fixed under the condition of high pressure, especially when it is closed. The upper stem and the lower support shaft decompose part of the pressure from the medium, so the ball does not shift to the downstream, so the pressure on the downstream valve seat is relatively small, so the friction force that the valve overcomes when it acts is small, so the valve seat is ground. Small damage, the long service life of the valve, especially for frequently operated valves, this structure is more suitable.

Gate Valve

The core of the gate valve is a wedge valve plate or parallel valve plate. There is no supporting shaft at its lower part. Therefore, when the valve is in the high-pressure application and in the closed state, the valve plate bears a great pressure from the medium. Because of the flat gate valve plate structure, all the medium pressure acts on the valve plate at the same time, the valve plate will be dead pressed to the downstream valve seat (at the same time, the excessive pressure acts on the vertical surface of the valve plate, making the valve plate whether wedge-shaped or parallel double ram. There will be some deformation), so the valve needs to overcome great friction when it is opened, so the life of the valve printed by the wear of the valve seat is short.

Valve seat of gate valve and ball vave

There is a spring in the valve seat of the ball valve, and the sealing design of the valve seat makes it difficult for the dregs in the medium to enter the valve seat. The valve seat contacts with the valve ball for a long time under the action of spring, so when the valve acts, the valve seat has a certain scraper function, which can scrape off the residue attached to the valve core after long-term operation, so the sealing performance of the valve can be guaranteed for a long time. Especially in the application of high temperature and high pressure, because the materials of valve seat, valve body and valve ball are selected with the same thermal expansion coefficient and the valve seat with spring structure, when the valve is closed, the huge temperature difference and temperature drop will not affect the action of the valve, and the valve will not be locked. The valve seat is very narrow. In high-temperature application, when the valve is closed because the medium is not circulating, the temperature will drop, so the valve seat will be tightened, which will produce a great pressing force on the valve plate. When the valve is opened again, a large torque is needed to overcome this pressing force, which will cause great damage to the valve seat and affect the service life of the valve seat. Thus, the service life of the valve is affected. In addition, due to the self-weight of the gate itself when the valve is closed, it will bring great impact force and noise to the valve.

Itinerary of gate valve and ball vave

Ball Valve

The stroke of the ball valve is angle stroke, so the installation space is small and the height is low.

Gate Valve

The stroke of the gate valve is a straight stroke, so the installation space is large and the height is high.

Actuator of gate valve and ball vave

Due to the design of the trunnion ball, the torque value of its opening and closing is small, so the corresponding actuator is small. Because the valve plate has a large pressing force on the valve seat, it needs a large torque to overcome this large friction, and the actuator is equipped with a large amount of torque.

Medium flow direction of gate valve and ball vave

Double flow direction, no installation flow direction problem on site.
Generally, it is a single flow direction.

Service life of gate valve and ball vave

The ball valve has a longer service life, while the gate valve’s service life is relatively short.

Maintenance of gate valve and ball vave

Ball Valve

The ball valve generally does not need maintenance, especially the ball and valve seat. Due to the small wear, it does not need to be replaced within 5 years.

Gate Valve

The gate valve needs regular maintenance due to the large wear of the valve seat

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1. Ball Valve Working Principle and Gate Valve Working Principle

Ball valve: the opening and closing parts (ball) is driven by the valve rod and rotate around the axis of the ball valve. The ball valve is mainly used to cut off, distribute and change the flow direction of the medium in the pipeline. It can be closed tightly with only 90-degree rotation and a small rotation torque. The ball valve is most suitable to be used as a switch and shut-off valve, a v-ball valve.

Gate valve: the gate is the gate, the movement direction of the gate is perpendicular to the direction of the fluid, the gate valve can only be fully open and fully closed, and cannot be adjusted and throttled. The gate valve is sealed by contact between the valve seat and the gate. Usually, the sealing surface will be overlaid with metal materials to increase wear resistance, such as overlaying, stainless steel, etc. The ram has a rigid ram and elastic ram. According to the different rams, the gate valve is divided into a rigid gate valve and an elastic gate valve.

2. Characteristics of Ball Valve vs Gate Valve

Ball valve: wear-resistant; good sealing performance; because the seal of hard seal ball valve is manually ground, it can only be used until the valve core and sealing ring are completely consistent.

Therefore, its sealing performance is reliable; the switch is light; because the bottom of the sealing ring of the hard sealed ball valve uses a spring to tightly hold the sealing ring and the valve core together, the switch is very light when the external force exceeds the pre tightening force of the spring; the service life is long.

Gate valve: lightweight, the body is made of high-grade nodular cast iron, the weight is about 20% ~ 30% lighter than the traditional gate valve, convenient for installation and maintenance; flat bottom gate seat; the whole body is covered with glue, not easy to fall off and has good elastic memory; precision casting is used for the precision casting of the valve body, and the precise geometric size makes the valve body without any finishing to ensure the tightness of the valve.

3. Operation Differences of Gate Valve vs Ball Valve

A ball valve uses a rotary ball with a bore and a stem as seen in Figure 1. 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. 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.

4. Common Application of Gate vs Ball Valve

Ball valves and gate valves are both extensively utilized in residential and industrial applications. However, these two types have differences in their usage:

• A ball valve is better suited for applications that require rapid opening and closing speeds or during crises due to its quarter-turn on/off function. A gate valve takes longer to operate than a ball valve since it requires more than a 360° turn.
• Gate valves are commonly found in older plumbing systems that do not require frequent shutoffs. They are used in large water supply systems because of their direct flow path and lack of flow constraints, whereas ball valves are increasingly being employed in new plumbing systems that require frequent shutoffs.
• Low-pressure applications are suited for both ball and gate valves. A gate valve, on the other hand, is better suited to high-pressure applications. This is due to the ball valve’s rapid opening and closing, which can create a water hammer.
• Since gate valves are easier to clean and maintain, they are commonly employed with slurries and viscous media while ball valves are not ideal for this end; because they are hard to clean, and slurry particles can harm the rotary ball.
• Ball valves are frequently utilized in fire suppression and marine applications. Ball valves are hard to clean and may cause contamination, thus they are best avoided in food, beverage, and pharmaceutical applications.
• Gate valves are utilized in high-temperature, high-pressure settings such as power plants, mining, and water treatment.

Are Ball Valves Better than Gate Valves?

To settle the ball valve vs gate valve debate, we opened up the discussion to leading Scottish industrial valve distributors, BM Engineering Supplies, who stock both valve types. They stated that the benefit of a ball valve vs a gate valve is that they seal much tighter, therefore making them better at avoiding leakage than gate valves. This is due to their 100% shut-off characteristics. In addition, they are also easier to use than gate valves, offering both lower rates of failure and greater longevity.

The durability of ball valves makes them an ideal choice for shutoff applications. They perform consistently well after many cycles, as well as boasting reliability and the ability to close securely even after long periods without use. For these reasons, they are often preferred over gate and globe valves.

ZECO company supplies both ball valves and gate valves with high quality. Click to know more about our ball valves for sale and gate valves for sale. We are sure to provide you with the best service.

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What is a Gate Valve?

Gate valves, also known as sluice and shut-off valves. They are usually operated using a circular handwheel which when turned can lower or raise the valve gate to control the flow of medium.

Gate valve is the most common valve used in water, oil and gas supply systems. It is a linear motion isolation valve that is capable of stopping or allowing flow. These valves should not be used to regulate flow; they should be used to open fully or close completely, as partial opening can cause injury. The name ‘gate valve’ comes from the fact that the closing section slides into the flowing fluid to create a shut-off and therefore acts as a gate. Gate valves are used to isolate specific parts of the pipeline network for maintenance, repair and new installation operations, as well as to redistribute the flow of media throughout the pipeline.

Gate valves are typically used for larger pipe diameters, from 2″ to the largest, as they are less complex to construct than other larger sized valves. Gate valves are available in a variety of sizes, materials, temperature and pressure ratings, as well as gate and bonnet designs. There are gate valves with electric and pneumatic actuators, however manual gate valves are more cost effective as they are not used as often.

The gate valve is one of the most frequently used valves today due to its simple design and ability to be used in a variety of low pressure drop applications. Gate valves are designed to be full bore. This indicates that the valve port is the same size as the inner diameter of the connecting pipe. The full bore gate valve allows fluid to flow without being blocked and without causing a pressure drop in the pipe. This also makes it possible to use a cleaning pig to clean the pipe.

What is a Ball Valve?

Ball valve, also known as a shut-off valve valve. Ball valves use a handle to control the position of a ball with a hole in the mechanism. When the handle is turned, the hole immediately opens or closes the flow of water.

You can tell whether a ball valve is open or closed by the position of the handle: when open, the handle is flat and aligned with the flow of water, when closed, the handle is perpendicular to the flow of water.

Ball valves, as the name suggests, use a rotatable ball with a hole to control the flow of liquids and gases from one opening to the other. The medium can flow through, or be stopped by turning the ball a quarter turn (90 degrees) about its axis. These valves regulate the flow by allowing the opening to be opened, blocked or partially opened. Ball valves are the best choice for use with gases as they have a stronger seal. They can withstand pressures of up to 700 bar and temperatures of up to 350°C and their sizes usually range from 0.5″ to 48″. Because of their simple construction, they are easy to use and maintain.

Ball valves are reliable, close safely even after long periods of standstill, and are durable and still work well after many cycles. They have a higher resistance to contaminated media than most other types of valves, ensuring a good seal even if the media is not clean. These features make them the best choice for shut-off and control applications where gate and globe valves are often chosen, but they lack the fine control of these alternatives in throttling applications.

Difference between Gate Valves and Ball Valves

One of the most important components of a functional plumbing system is the valve it contains. Valves allow the start and stop of fluid flow, and they need to work well to prevent leakage and excess flow. Although there are many types of valves on the market, the two most common are ball valves and gate valves. This is the information you need to know about the two valve types.

Operation Differences

Ball valves use a rotating ball with a hole and a stem. When the handle attached to the stem is turned, it rotates the ball to open or close the valve. This type of valve is also known as a quarter-turn valve because the handle only needs to be turned 90° (a quarter turn) to allow or stop the flow of the medium. When the handle is parallel to the pipe the valve is open and when the handle is perpendicular to the pipe the valve is closed. For a more in-depth analysis of ball valves, please see our ball valve technical article.

Gate valves use a gate to control the flow of media. The gate is a solid disc structure attached to the stem. The gate is lifted to open the valve and lowered back into position to close the valve. The valve has a bonnet which controls the position of the gate when rotated. This type of valve is also known as a multi-turn valve as it requires more than 360° of rotation to fully open or close the valve. For a more in-depth analysis of gate valves, please see our gate valve technical article.

Valve Seal Capacity Differences

For ball valves, the seal can be fixed for floating ball valve designs or floating for trunnion mounted ball valves. As ball valves are typically used in low pressure applications, given the nature of their operating mechanism, the main seal is usually made of PTFE and other related materials.

Whilst the fast closing and opening of a ball valve is advantageous, this can also cause some problems. Ball valves are susceptible to water hammer or sudden surges in pressure when the valve is closed. This situation can damage the seat of the ball valve.

In addition, water hammer can increase the pressure inside the ball valve. In applications where this can occur, i.e. with combustible materials, there is an emergency valve seat seal, usually made of metal. This is a second barrier in conditions where the resilient seal is damaged in high pressure service. To relieve the pressure, the ball valve can be fitted with a pressure relief device.

The gate valve reduces the pressure drop to a minimum when fully open. This is achieved by using a full orifice design. This means that the size of the valve is equal to the size of the pipe. It is this feature of the gate valve that gives it an advantage over the ball valve. Water hammer does not occur in gate valves.

What is better a gate valve or ball valve?

Ball valves have their advantages and disadvantages, as do gate valves. Ball valves create a tighter seal more effectively, are more reliable and last longer than gate valves, but tend to be more expensive. They are typically used for shut-off and control applications. As ball valves can be opened and closed immediately they are more prone to water hammer than gate valves. So choose gate valve or ball valve, Please make your choice based on the following advantages and disadvantages, or contact ZECO commercial@zecovalve.com to make your selection

Advantages of gate valves

• Low fluid resistance; gate valve body is straight-through design, does not change the flow direction, so that the fluid through the valve (fully open) the least resistance.

• Superior sealing performance; the sealing performance of the globe valve is not as good as that of the gate valve. The gate valve has a faster and easier opening and closing mechanism than other globe valves.

• Bi-directional; gate valves can flow in both directions. They are not limited to one-way flow and are not influenced by the direction of media flow. Gate valves are therefore suitable for use in pipelines with different flow directions.

• Gate valves have a wide range of applications; they are highly adaptable and can be utilised in a variety of media, including steam, oil and other liquids. In addition, the gate valve can be used for media with granular substances and high viscosity. It can also be used as a low vacuum system valve and exhaust valve.

Disadvantages of gate valves

• The opening and closing speeds are slow and the valve must be lifted to the upper part of the chamber during opening and must fall into the seat during closing. As a result, the valve must move a considerable distance to open or close, resulting in long opening and closing times.

• Prone to scratching; excessive friction between the two sealing surfaces of the gate and the valve seat during opening and closing, resulting in scratches on the sealing surfaces. These scratches may seem insignificant at first, but will eventually have an impact on sealing performance and service life.

Advantages of ball valves

• Efficient sealing performance; among other types of valves, the ball valve has a good sealing performance with no leakage.

• Robust; able to withstand high pressures of up to 700 bar and more. They can also withstand high temperatures of up to 350°C.

• Easy to use; available in flanged, welded, threaded, duplex, triple clamp and thin-walled versions. It is simple to set up and use.

• Easy to repair and maintain, extending service life.

• Economical; cost effective valve for any application required.

• Versatile; available as 2-way and 3-way ball valves to convey, divert and converge media.

Disadvantages of ball valves

• Wear and tear; if suspended particles are present in the medium, the valve body and ball valve will wear down, and the valve may be struck.

• More expensive price.

• More possibilities for water hammer

Why is ball valve preferred over gate valve?

In contrast to gate valves, ball valves provide a tight seal and have a complete shut-off characteristic. Therefore, ball valves are more suitable for applications such as natural gas where a proper long-term seal is important

Can I replace gate valve with ball valve?

Because gate valves and ball valves have the same function, then the structural length of gate and ball valves, whether EN558 or AMSE B16.10 or other national standards, are the same structural length for the same bore pressure, so we can be replaced at any time

We are gate valve & ball valve suppliers. If you are interested in our products, please feel free to contact us.

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Ten articles before and after

Intro to Globe Valve

Globe Valve Vs Gate Valve

Pros of Gate Valve

What Is a Globe Valve And When Is It Made Use Of?

Why Do We Use Butterfly Valve?

Check Valve: The Most Important Valve In a Process System

Backflow Preventer vs. Check Valve: What’s the Difference?

Sealing Elements Of Low-Temperature Bar Ball Valve

The Distinction Between a Butterfly Valve As Well As Gate Valve

Precautions For Ball Valve Repair And Maintenance

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