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Description:
Butterfly valve, a valve that regulates or isolates the flow of the fluid in the system. The valve is a disc that is connected to a rod. The ability of butterfly valves include start, stop or restrict the flow in the pipeline system; these allow the valve to repair, clean, or change the fluid in the circumstance that no fluid flowing through the pipeline. The name of the butterfly valve does not come from its physical appearance. It runs in a quarter turn, the valve must be fully opened during a 90-degree rotational movement to be fully closed. Therefore, the valve can open and close quickly. Thus, the name of the butterfly originated from the fact that discs or wings move around the central axis, just like the body of a butterfly. We offer the butterfly valve from sizes ranging 1 1/2" to 6” (DN40-150). The material is cast iron, it can withstand 150 PSI of working pressure. |
Brand:
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Different Types of Butterfly Valves
Product Information of Butterfly Valves
1. What is a butterfly valve used for?
In general, the valve can be manipulated in a manual way by handles and gears, or it can be manipulated automatically by electric, pneumatic or hydraulic actuators. These devices enable the disc to rotate precisely to the position from the completely open to the closed position.
Manual actuation is considered an economical and costless method. Most importantly, it is easy to use and operate. The two commonly used methods are handles and gears:
(a) Hand Lever: Suitable for small size valves, which can be locked in open, partially open or closed positions.
(b) Gear: Suitable for slightly larger valve sizes and use gearboxes to increase torque at the expense of lower opening or closing speeds. The gear operated valve is self-locking and due to this reason, it can be equipped with a position indicator.
Automatic actuation is one of the reliable ways to control and monitor the valve remotely. Actuators increase the possibility of making fast operation of large valves. The function of an actuator is to:
There are three types of automatic actuators, which include:
(a) Electric: Utilize an electric motor to monitor the valve by turning the valve stem
(b) Pneumatic: Able to move a diaphragm or piston to monitor the valve, however, compressed air is required.
(c) Hydraulic: Able to move a diaphragm or piston to control the valve, however, hydraulic pressure is required.
Besides, the butterfly valve is composed of main components such as valve seat, valve disc, valve body, and actuator.
(a) Seat: The use of rubber as material to the seat is to ensure the tightness and the security of sealing when the valve is in a closed position. In the circumstance that the valve stops operating as usual, the valve seat may have been damaged.
(b) Disc: The disc is a key component in the valve system. When the valve flap rotates, the valve opens, it will present the valve flap a butterfly-like appearance. The disc can be in a fully closed or open position, as it is moved by an actuator or a manual handle.
(c) Body: The purpose of the body is to connect valves with pipes or fittings. It is everything around the valve seat and constitutes an important part of the valve structure.
(d) Actuator: Also named as handle or operator, it monitors the degree of opening or closing of the butterfly valve, and it is a handle that can move 90 degrees. The actuator is an alternative installation because the standard valve comes with a handle.
Furthermore, the operation is similar to a ball valve and can be closed quickly. Butterfly valves are always the popular choice due to being less costly than other valves and are lighter in weight, therefore it requires less support. There is a disc placed in the centre of the pipeline, it is supported by the actuating rod which connects outside the valve. Rotate the actuator to make the disk parallel or perpendicular to the flow. Unlike a ball valve, the valve flap is always present in the fluid, so it will cause a pressure drop even when it is opened.
Butterfly valves is come from a series of valves called quarter-turn valves. In operation, when the disc rotates a quarter turn, the valve is fully opened or closed. When the valve is closed, the valve flap is rotated to fully block the path. When the valve is fully opened, the valve flap rotates a quarter turn, allowing fluid to pass through almost unrestricted. The valve can also be opened gradually to throttle flow.
In general, the valve can be manipulated in a manual way by handles and gears, or it can be manipulated automatically by electric, pneumatic or hydraulic actuators. These devices enable the disc to rotate precisely to the position from the completely open to the closed position.
Manual actuation is considered an economical and costless method. Most importantly, it is easy to use and operate. The two commonly used methods are handles and gears:
(a) Hand Lever: Suitable for small size valves, which can be locked in open, partially open or closed positions.
(b) Gear: Suitable for slightly larger valve sizes and use gearboxes to increase torque at the expense of lower opening or closing speeds. The gear operated valve is self-locking and due to this reason, it can be equipped with a position indicator.
Automatic actuation is one of the reliable ways to control and monitor the valve remotely. Actuators increase the possibility of making fast operation of large valves. The function of an actuator is to:
- Fail-open, which keeps open when the actuator fails;
- Fail-closed, which keep closed when the actuator fails; and
- Usually have a manual drive method in the event of any failure.
There are three types of automatic actuators, which include:
(a) Electric: Utilize an electric motor to monitor the valve by turning the valve stem
(b) Pneumatic: Able to move a diaphragm or piston to monitor the valve, however, compressed air is required.
(c) Hydraulic: Able to move a diaphragm or piston to control the valve, however, hydraulic pressure is required.
Besides, the butterfly valve is composed of main components such as valve seat, valve disc, valve body, and actuator.
(a) Seat: The use of rubber as material to the seat is to ensure the tightness and the security of sealing when the valve is in a closed position. In the circumstance that the valve stops operating as usual, the valve seat may have been damaged.
(b) Disc: The disc is a key component in the valve system. When the valve flap rotates, the valve opens, it will present the valve flap a butterfly-like appearance. The disc can be in a fully closed or open position, as it is moved by an actuator or a manual handle.
(c) Body: The purpose of the body is to connect valves with pipes or fittings. It is everything around the valve seat and constitutes an important part of the valve structure.
(d) Actuator: Also named as handle or operator, it monitors the degree of opening or closing of the butterfly valve, and it is a handle that can move 90 degrees. The actuator is an alternative installation because the standard valve comes with a handle.
Furthermore, the operation is similar to a ball valve and can be closed quickly. Butterfly valves are always the popular choice due to being less costly than other valves and are lighter in weight, therefore it requires less support. There is a disc placed in the centre of the pipeline, it is supported by the actuating rod which connects outside the valve. Rotate the actuator to make the disk parallel or perpendicular to the flow. Unlike a ball valve, the valve flap is always present in the fluid, so it will cause a pressure drop even when it is opened.
Butterfly valves is come from a series of valves called quarter-turn valves. In operation, when the disc rotates a quarter turn, the valve is fully opened or closed. When the valve is closed, the valve flap is rotated to fully block the path. When the valve is fully opened, the valve flap rotates a quarter turn, allowing fluid to pass through almost unrestricted. The valve can also be opened gradually to throttle flow.
2. What is the defference between wafer type and lug type butterfly valve?
The butterfly valve can be connected to the piping system in a variety of ways. Wafer type and lug type are the most popular methods. Yet, they can also be connected using flanges or tri- clamps.
The butterfly valve can be connected to the piping system in a variety of ways. Wafer type and lug type are the most popular methods. Yet, they can also be connected using flanges or tri- clamps.
ANSI 150# Cast Iron Wafer Type Butterfly Valve​
(a) Wafer Type
Wafer type is the most popular and costless option, it is sandwiched between two pipe flanges. The valve can choose to have flange holes on the outside of the valve body. The pipe flange is connected by a long bolt that runs through the entire valve body, and the seal between the valve and the pipe flange is realized by the gaskets on both sides of the valve, the flat valve and the O-ring surface. The connection is designed to seal the two-way pressure difference and prevent backflow in systems designed for universal flow. To replace the valve or pipe, the system needs to be shut down. |
ANSI 150# Cast Iron Lug Type Butterfly Valve​
(b) Lug Type
The lug type has threaded inserts on both sides of the valve body. Two sets of bolts connect the pipe flange to each side of the bolt insert, with bolt threads in the middle and no nuts. This design can disconnect one side without affecting the dead-end connection service on the other side. When the valve is installed between two flanges, a separate set of bolts is used on each flange side. It is recommended to use lug valves for dead-end services, which usually have a lower operating pressure rating. In this way, each section of the pipeline can be disassembled and replaced independently. Basically, there are 8 or 12 lugs, of which 4 or 6 lugs are used to connect each pipe segment line. Unlike the wafer type, the lug type can carry the weight of the pipe through the valve body. |
3. What is the purpose of the butterfly valve?
The applications of Butterfly Valves are in a wide range, it is generally used in the mass water and mud.
These are the examples of the common application of butterfly valves:
Vacuum service
The applications of Butterfly Valves are in a wide range, it is generally used in the mass water and mud.
These are the examples of the common application of butterfly valves:
Vacuum service
- Chemical and oil industries
- Power generation
- Slurry and similar service
- Compressed air and gas
4. What are the advantages of using butterfly valve?
East and fast to open |
Rotate the handle 90 degrees to completely close or open the valve. Large valves require a gear box in which the handwheel is connected to the valve stem by gears. Thus, the valve operation has been simplified. |
Lesser space requirements |
Compared with other valve designs, this compact design requires much less space. |
Economical choice |
The design of the valve requires less material, the wafer type of butterfly valve is the most inexpensive and lowest-budget choice, it fits between two pipeline flanges. On the other hand, the lug type is fixed between the two pipe flanges by bolts that connect the two flanges and pass through the holes on the valve housing. |
Require less maintenance |
The high reliability characteristic requires less maintenance. The reason is due to the reducing level of ware which enables a longer use life. As the low requirement of maintenance can minimize the operating cost. |
5. What is the main disadvantage of butterfly valve?
Butterfly valves are widely used in large-diameter industrial and water plant piping systems due to their lightweight, simple structure, and quick operation. However, the presence of cavitation may result in noise, vibration, and rapid deterioration of valve internals, and no further operation is allowed. Therefore, the monitoring of cavitation has economic significance and is very important in industry.
Cavitation: As the usage of butterfly valves is mainly in flow control valves, due to the small opening of the valve, cavitation may happen in the higher flow range. When the liquid passes through the pipe, the velocity is relatively low due to the large cross-section. As the liquid passes through the valve seat, its velocity increases. The increase in speed will increase the dynamic pressure, thereby reducing the static pressure. If the speed is high enough, the pressure at the valve seat will drop below the vapor pressure of the liquid and form vapor bubbles. The downstream static pressure is usually higher than the vapor pressure of the liquid. Therefore, the bubbles or cavities of the steam implode. When the bubble bursts, all the energy is concentrated in a very small area. This will generate a huge pressure of thousands of pounds per square inch in a small area, generating tiny shock waves. These shock waves hit the solid part of the valve. Repeated implosion on a small surface will eventually cause the metal to fatigue and wear the surface. Cavitation is a potential hazard, especially when the valve is operated at a low opening, it may quickly damage the valve. It is suggested that simultaneous chemical attacks will accelerate pitting and erosion, or high impact pressure will cause local high temperatures to accelerate pitting.
In order to detect the cavitation of the butterfly valve, a support vector machine can be used. According to a research focus on cavitation detection of butterfly valve using support vector machines, the authors study a new scheme for butterfly valve cavitation detection in large pumping stations based on two classifiers SVM and SOFM. Extract the stationary characteristics of the vibration acceleration signal from the statistical moments. The classifier is trained and then classifies the valve's normal (non-cavitation) and cavitation state. The test results prove that the trained classifier has the ability to detect cavitation. The classification accuracy of SVM is better than SOFM, and it provides 100% success rate for training set and test set. The system can provide potential uses for real-time implementation, thereby making it possible to develop automatic valve condition monitoring and diagnostic systems. In addition, this is essential for valve monitoring strategies, as it can be used to detect problems before serious failures occur and help schedule valve repairs in a timely manner.
Butterfly valves are widely used in large-diameter industrial and water plant piping systems due to their lightweight, simple structure, and quick operation. However, the presence of cavitation may result in noise, vibration, and rapid deterioration of valve internals, and no further operation is allowed. Therefore, the monitoring of cavitation has economic significance and is very important in industry.
Cavitation: As the usage of butterfly valves is mainly in flow control valves, due to the small opening of the valve, cavitation may happen in the higher flow range. When the liquid passes through the pipe, the velocity is relatively low due to the large cross-section. As the liquid passes through the valve seat, its velocity increases. The increase in speed will increase the dynamic pressure, thereby reducing the static pressure. If the speed is high enough, the pressure at the valve seat will drop below the vapor pressure of the liquid and form vapor bubbles. The downstream static pressure is usually higher than the vapor pressure of the liquid. Therefore, the bubbles or cavities of the steam implode. When the bubble bursts, all the energy is concentrated in a very small area. This will generate a huge pressure of thousands of pounds per square inch in a small area, generating tiny shock waves. These shock waves hit the solid part of the valve. Repeated implosion on a small surface will eventually cause the metal to fatigue and wear the surface. Cavitation is a potential hazard, especially when the valve is operated at a low opening, it may quickly damage the valve. It is suggested that simultaneous chemical attacks will accelerate pitting and erosion, or high impact pressure will cause local high temperatures to accelerate pitting.
In order to detect the cavitation of the butterfly valve, a support vector machine can be used. According to a research focus on cavitation detection of butterfly valve using support vector machines, the authors study a new scheme for butterfly valve cavitation detection in large pumping stations based on two classifiers SVM and SOFM. Extract the stationary characteristics of the vibration acceleration signal from the statistical moments. The classifier is trained and then classifies the valve's normal (non-cavitation) and cavitation state. The test results prove that the trained classifier has the ability to detect cavitation. The classification accuracy of SVM is better than SOFM, and it provides 100% success rate for training set and test set. The system can provide potential uses for real-time implementation, thereby making it possible to develop automatic valve condition monitoring and diagnostic systems. In addition, this is essential for valve monitoring strategies, as it can be used to detect problems before serious failures occur and help schedule valve repairs in a timely manner.
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