Advantages And Disadvantages Of Butterfly Valves And Gate Valves

Differential pressure: Gate valves are usually much better than butterfly valves when executed under pressure. Their building structure shows that the flow can continue without producing any kind of unnecessary pressure changes. And their use is not very proactive.

This is not the case with butterfly valves. Their revolving gate structure shows that the holding gate bears a greater pressure difference. This is equivalent to the need for greater toughness to operate a butterfly valve. This is usually solved by using a larger butterfly valve with a long arm.

Wear and tear: Gate valves are often better than butterfly valves in terms of service life. The actual style of this valve ensures that it will not be subjected to high pressures like a butterfly valve during operation. Although modern butterfly valves have higher stress resistance, unfortunately, their design ensures a higher wear price. Unlike gate valves, no matter whether the valve is open or closed, its seal is always directly exposed to the flow. When opened, parts of the gate valve are revealed to flow for really short ruptures of time.

Safety: This depends on the use of the valve and the pressure it may encounter. A knowledgeable designer who recognizes what these valves can and cannot do can completely prevent this problem. Nevertheless, it is necessary to understand and recognize that butterfly valves were not originally designed to handle high-speed cycles. Of course, 6m/s is the best flow rate recommended for this valve. Anything above the above will subject the butterfly valve to a dangerous stress difference, which will increase wear and may lead to early failure and collapse.

High-pressure drop: Another problem that affects the butterfly valve is the drop in pressure when it is released. Nowadays, in order to save electricity, the entire system must maintain high pressure, which is one of the reasons why gate valves and other alternatives have become popular again.

Price: Butterfly valves are often cheaper than gate valves.

Size: The butterfly valve is smaller and smaller. Generally, this makes them much more flexible in use than gate valves.

These two valves are destined to be used as a channel flow, not as a regulating valve. Both are not developed and utilized. Once they are released, the flow is out of control.

The Difference Between Ball Valve And Gate Valve

Gate valves and ball valves are commonly used valves to control flow, but there are important differences between them.

All types of valves are essential to operate countless versions of machinery and equipment, spanning many industries and applications. It is hard to imagine an environment without valves. Having said that, not all valves are the same, and they are definitely not one size fits all parts.

It is important to choose the right valve, so understanding the application, advantages, and advantages of each valve is the key.

Understand the ball valve

The main difference between ball valves and gate valves is their structure. They work similarly but have different structures.

Ball valves are so-called because they have a stem and a ball. There is an opening inside the ball. When the valve is opened, this opening is aligned with the pipe, allowing free flow. Turn the control lever to rotate the ball so that the opening is perpendicular to the flow and close it.

These valves are also very durable and can be used for a long time even in the case of heavy use or long periods of non-use. Ball valves are reliable, but they do not provide good control, so in situations where you want a simple shutdown or start without fine-tuning the control, it is best to stick to ball valves. This is why many people simply refer to these valves as "shut-off valves."

When the operator needs to open and close the equipment without losing pressure, the ball valve is also an ideal choice. They have a good seal because the ball blocks the flow, and they are easy to operate, just simply turn the valve handle, and then it can be confirmed visually.

Having said that, the cost of ball valves may be a little higher than gate valves. Another potential disadvantage is the space required for ball valve operation. In order to use the ball valve lever, the operator needs to ensure that there is a complete 90-degree turn.

Understanding gate valves

Similarly, due to the difference in structure between ball valves and gate valves, the working principle of gate valves is different from that of ball valves. They control the flow through a gate that is lifted out of the passage for fluids or other materials. The door can be round or rectangular. The operator usually controls the valve by rotating the knob to raise or lower the gate, thereby controlling the flow.

The gate valve does not have the immediate closing function of the ball valve, which is one of the main differences. However, they do provide finer tuning control of material flow and flow pressure. The gate valve does not need to be closed immediately, but in applications where it is not required but with a high degree of control, the gate valve is a better choice than the ball valve. For example, in the case of high water pressure, the gate valve can prevent the formation of a water hammer.

Choose the right valve

The decision to use a ball valve or a gate valve depends on various factors, such as price, location and method of use, and the material passing through the valve. You may find that you have chosen one or both.

Pros And Cons Of Cast Steel Globe Valve

China cast iron globe valve supplier shares this article with you.

In recent years, since the appearance of the sealed valve, the medium flow direction of the cast steel globe valve has changed from above the valve disc to the valve cavity. At this time, under the action of the medium pressure, the force to close the valve is small, and the force to open the valve is large. The diameter of the valve stem can be reduced accordingly. At the same time, this type of valve is also tight under the action of the medium.

China cast iron globe valves to have a simpler structure than gate valves and are easier to manufacture and maintain. The sealing surface is not easy to wear and has good sealing performance. There is no relative sliding between the valve disc and the sealing surface of the valve body when opening and closing. Therefore, the abrasion is not serious, the sealing performance is good, and the service life is long. When opening and closing, the valve plate stroke is small, so the height of the cast steel globe valve is smaller than that of the gate valve, but the structural length is larger than that of the gate valve. Closing is more laborious, and the principle is the time to open and close the door.

The fluid resistance is large because the medium passage in the valve body is tortuous, the fluid resistance is large, and the power consumption is large. When the nominal pressure PN≤16MPa, the medium flow direction is generally adopted, and the medium flows upward from the valve disc; when the nominal pressure PN≥20MPa, the reverse flow is generally adopted, and the medium flows downward from the valve disc. Increase the sealing capacity. When the cast steel globe valve is in use, the medium can only flow in one direction, and the flow direction cannot be changed. When fully opened, the valve disc is often corroded. The stem axis of the cast steel globe valve is perpendicular to the sealing surface of the valve seat. The opening or closing stroke of the valve stem is relatively short, and it has a very reliable closing action, which makes the valve suitable for cutting off or regulating and throttling the medium.

Cons of carbon steel stainless steel globe valve:

The fluid resistance is large, and the force required for opening and closing is large. It is not suitable for media with large particles, high viscosity, and poor adjustment performance.

Pros of cast steel globe valve: double-sealed design if the bellows fail, the valve stem will prevent the packing from leaking, and conform to international sealing standards, no fluid loss, reduced energy loss, improved plant equipment safety, and have a long service life, reduce maintenance times, reduce operating costs, sturdy and durable bellows seal design, ensure zero stem leakage, and provide maintenance-free conditions. The bellows-sealed cast steel globe valve adopts a bellows-sealed design, which completely eliminates the shortcomings of ordinary valve stem packing seals, such as aging and easy leakage. It not only improves the use of energy efficiency, but also increases the safety of production equipment, reduces maintenance costs, and provides a clean and safe working environment.

Maintenance And Repair Tips Of Butterfly Valve

A butterfly valve is a kind of flow regulating device, which includes a rotating disk to operate the liquid flowing in the process. In the vertical position of the butterfly valve, there is a metal-based disc that operates the closing technology of the fluid flowing. The closing-off operation of this valve is exactly the same as the closing operation of a ball valve. Compared with the float ball valve, this valve has the following advantages:

Lightweight; therefore it does not require much support.

Compared with other similar valves with different designs, its cost is lower.

The butterfly valve is a reliable and close-fitting two-way valve, which is widely used in food, shipbuilding, and other industries. Compared with other valves, the installation of butterfly valves is definitely a cost-effective way. By closing the disc, the butterfly valve can also play a role in guiding the flow and closing the liquid/gas.

How to repair and maintain butterfly valves in different pipelines?

The following tips for butterfly valve maintenance can be given to you for your reference:

Butterfly valves need regular maintenance and repair after working in different working environments for a period of time. General maintenance can be divided into minor repairs, medium repairs, and heavy repairs.

The specific analysis depends on the environmental conditions of the pipeline. Because different industries require different maintenance and repair procedures, for example, in the pipeline maintenance of petrochemical enterprises, the pipeline pressure is required to be lower than PN16MPa, and the medium temperature is lower than 550°C. Different maintenance conditions are required for various physical and chemical pipeline transportation media.

The minor repair process of various pipeline butterfly valves, including cleaning nozzles and oil cups, replacing o-rings, cleaning threads and valve stems, removing debris in the valve, tightening screws, and configuring handwheels. All of these can be used as scheduled maintenance. Medium repair: including minor repair items, replacement of clean parts, valve body repair, sanding of seals, valve stem straightening, etc. These items can be used for an overhaul in the factory. Heavy repair: Included in the mid-repair project, replacement of valve stems, repair of brackets, replacement of springs and seals. When these are needed, the butterfly valve suffers huge damage.

In order to prevent rust and oiling, butterfly valves should be properly maintained.

At the top of the valve, there is a lubricating oil fitting. This may not be observed when the valve arrives. Make sure to apply grease to the neck of the valve at regular intervals until the excess grease flows out.

In the gearbox, you can use lithium-based grease for maintenance.

You can use any silicon-based product/lubricant to easily clean all parts of the valve.

If you do not use it frequently, please try rotating or cycling the butter valve once a month.

We are butterfly valve suppliers. Please feel free to contact us if you are interested in our products.

Ball Valve

Ball valves came out in the 1950s. It is a valve that has been used more and more in thermal systems in recent years. Its superior performance is unattainable by other valves. There is no fluid resistance, lightweight, good sealing performance, no leakage, and can be opened and closed. The advantages of fast switching, non-corrosion by medium, and long service life have gradually gained the favor of enterprise valve selection. However, how to perform routine maintenance and repair of valves in daily operation has also become a work that cannot be ignored by heating companies.

By understanding the working principle of the valve and the characteristics of the product, as well as the operation method and troubleshooting, the corresponding production operation system can be formulated in the company's normal production to ensure the safe operation of the valve equipment.

The correct use, installation, and maintenance of the ball valve are very important, and it is also the content that the heating company must refer to when formulating operating procedures. Scientific management and maintenance of the ball valve during construction can not only ensure safety but also reduce construction and operation management. Pay attention to the following aspects:

1) Use correct methods to load and unload the valve to avoid mechanical damage to the valve. When lifting the valve, do not tie the lifting belt to the valve stem or actuator for lifting. If the valve is operated in violation of regulations, the valve stem will bend, the valve stem seal will fail, and the turbine box will be destroyed.

2) Before the valve leaves the factory, the blind plates or covers should be sealed at both ends of the valve to prevent impurities such as water and sand from entering the valve cavity at the transportation and construction site, causing seal damage and corrosion.

3) At the construction site, the valves should be placed neatly and should not be placed randomly, otherwise the drain valve or the grease injection valve of the valve will be broken and damaged.

4) Before the welding construction of the fully welded ball valve, confirm that the valve is welded in the fully open position to avoid damage to the ball and scratches on the sealing surface caused by welding spatter. The welding temperature between the valve seats is controlled at 140 degrees.

5) After the water pressure test is completed, the water in the valve cavity should be drained to prevent corrosion and freezing.

The valve is the control component in the fluid conveying system. It has the functions of cutting off, adjusting, diverting, preventing backflow, stabilizing, diverting, adjusting the balance of medium flow, etc.

Valves are also one of the most typical equipment in thermal systems. The quality of the valve and whether the valve is reasonably selected according to the characteristics of the valve play a decisive role in the heating quality.

Since these valves are laid in-ground wells, they are not easy to find because they will run, leak, and drip. Under normal circumstances, it will only be discovered when the user complains, the inspection is discovered, or the equipment is damaged.

We are ball valves manufacturers. Please feel free to contact us.

Gate Valve Problems

A household gate valve is used to close the gravity water supply well, which is currently under repair to temporarily shut off the water supply.

My gate valve is stuck and open, what should I do

If your gate valve is open and you cannot close it, then the only option is to drain it. In some cases, plumbers can quickly replace valves, but this does not pose a risk. In most cases, when your gate valve has a problem, if your gate valve is open, it is best to drain the water.

The problem that the gate valve cannot be opened

If you have a gate valve that cannot be opened, it is usually due to a broken spindle. The reason for this usually rest is that when the valve is closed due to not dirty build, scale, or other, the plumber or master will tighten the thread causing the thread to break. If the valve cannot be easily closed, it is best to replace the gate valve while draining water, so as to further avoid gate valve problems and cause more costs.

How to replace the gate valve without losing hot water

The best way to replace the valve is to freeze the pipe first, and then replace the valve. The only other way is to close the gate valve and disconnect the bottom pipe. Once you leave the top nut of the supply pipe, you can switch the valve very quickly. This must be done by a skilled emergency plumber.

My gate valve can’t close properly, why?

The reason why the valve cannot be closed normally is that as the gate valve ages, you will find dirt or scale accumulation, causing the closing mechanism to fail to close normally. The best way to solve this problem is to either clean the valve thoroughly or replace the gate valve.

When replacing the gate valve, whether it must be emptied first

As explained in the previous paragraph, to replace any valve, you don’t always have to empty it, as long as you have the experience and tools to do so.

What causes the gate valve to rupture

The reason for the rupture of the gate valve is that the valve is fragile and the pressure is too high when the gate valve is closed. The spindle thread is not deep enough to enter the valve, so if the pressure is too great, there is not much room to stop any resistance. It's a bit like breaking a twig instead of breaking a stick.

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

Why Do We Use Butterfly Valve?

The butterfly valve is a quarter-turn rotary motion valve used to stop, adjust and start the flow.

The butterfly valve can be opened easily and quickly. The 90° rotation of the handle provides complete closing or opening of the valve. Large butterfly valves are usually equipped with a so-called gearbox, where the handwheel is connected to the valve stem by a gear. This simplifies the operation of the valve, but at the expense of speed.

Due to its small size, simple structure, and lightweight, butterfly valves are increasingly used in piping systems such as cold and hot air, water and electricity, environmental protection, building water supply and drainage, and municipal engineering. Used as a medium for intercepting or intermediary flow. On many occasions, due to the advantages of the butterfly valve itself, it has been possible to replace gate valves, globe valves, ball valves, and other valves in industrial pipeline applications.

The structure of the butterfly valve is very simple, with only a few simple parts such as the valve body, valve stem, valve disc, valve seat, and transmission. Although the structure is simple, the function of the butterfly valve cannot be underestimated. The small structure has great practical value.

The butterfly valve can be used to adjust the flow. When the flow adjustment butterfly valve needs to be under special working conditions, or in a sealed environment, the performance requirements are strict, or the operating conditions of the butterfly valve are severely worn, low temperature, and other harsh work. You can use ANSI Butterfly Valve.

Advantages of the butterfly valve

Compared with other types of valves, butterfly valves have many advantages.

Compact design; small space requirements.

Lightweight; easily supported by the piping system.

Fast operation; reduce opening or closing time.

Easy to install.

The operating torque is small and the operation is simple.

Available in very large sizes.

Improve energy efficiency.

Low-pressure drop, high-pressure recovery.

The long service life of the valve.

The construction cost is relatively low.

The number of parts is small; therefore, maintenance is reduced.

Disadvantages of butterfly valves

However, the butterfly valves listed below have few disadvantages.

Throttle applications are limited to low dropout.

The disk motion is affected by the turbulence of the flow.

The valve disc is always under pressure, even if it is in the open state, it will interrupt the fluid flow.

The possibility of cavitation and blocked flow is a concern.

Poor sealing function.

Not suitable for the high-pressure difference.

Here are some reasons why it is best to install a butterfly valve over a gate valve:

Due to its lightweight and small space requirements, butterfly valves are easier to operate and install into applications.

Compared with gate valves, the face-to-face size of butterfly valves is much smaller, and it is an ideal valve used in small spaces.

The butterfly valve is easier to operate and reduces faster opening and closing-it only takes a quarter of a turn to fully open and close the valve.

Butterfly valves have a much shorter shaft than gate valves, which means there are fewer access problems.

Due to lower requirements and lighter weight, butterfly valves are generally cheaper.