Language
What Is Butterfly Valve?
Butterfly valve is a simple control valve that can also be used to control the on and off of a low-pressure pipeline medium. Butterfly valve refers to a type of valve whose closing part (disk or plate) is a disk and rotates around the valve axis to open and close. It basically cuts off and throttles the pipeline. The opening and closing part of the butterfly valve is a disc-shaped plate that rotates about its own axis in the valve body so as to achieve the purpose of opening and closing or adjusting.
Rich experience
The company' s founder team graduated from mechanical and electrical automation majors and has been engaged in the valve industry for more than 20 years. It is committed to providing customers with a complete set of fluid control solutions. It is a company integrating scientific research and development, A large-scale valve enterprise integrating testing and testing, manufacturing and sales.
Wide product range
The company mainly produces API 6D pipeline ball valves, gate valves, globe valves, check valves, plug valves and API 609 series butterfly valves in 6 categories, with more than 1,000 specifications and varieties. Products widely cover petrochemical, coal chemical, nuclear power, LNG, marine, aerospace, metallurgy, papermaking and other industries.
Complete qualifications
The company has a complete international standardized management system, adopts the world's top precision casting technology and modern intelligent electronic detection system, and uses advanced SAP resource management, strip storage management system and ERP system to effectively manage the factory.
High standard products
After years of hard work and development, it has become a key backbone enterprise in the valve industry. It specializes in improving the innovation and manufacturing capabilities of special valves in harsh industrial environments. High-quality products and fast after-sales service have won praise and trust from customers at home and abroad.
Advantages of Butterfly Valve
Lightweight and compact
With a compact design and a smaller face to face dimension, butterfly valves have a considerably less installation footprint and offer savings in the form of lower installation costs including labour cost, equipment, and piping support.
Low maintenance requirements
An inherently simple, economic design that consists of few moving parts, and hence fewer wear points, significantly reduces their maintenance requirements.
Fast acting
A 90° rotation of the handle, or the actuation mechanism, provides a complete closure or opening of the valve. However, with larger butterfly valves, a gearbox is often required as part of the actuation mechanism which reduces the operational torque and simplifies the operation of the valve but comes at the expense of speed.
Low cost
Owing to their simple design, butterfly valves require less material and are simpler to design and manufacture and are often the more economical choice compared to other valve types. The cost savings are mainly realized in larger valve sizes.
Versatility
Butterfly valve has a wide variety of use cases including the ability to be installed underground.
Bi-offset butterfly
The Bi-offset Butterfly Valve is a type of butterfly valve that is widely used in industrial applications. It is designed to control the flow of fluids, gases, and other materials in pipes, ducts, and other passageways.
Centre-pivoted butterfly valve
The Center Line Butterfly Valve is a high-performance valve that is designed to provide efficient flow regulation and control for various applications. As a trusted manufacturer based in China, we are proud to offer this outstanding product to merchants in countries outside of China.
Valve body
The valve body contains the different parts of the butterfly valve. There are primarily two types of valve bodies – wafer-style and lug body. The wafer-style body has a simple design compared to the lug body type – for connecting the pipes, the body features bolt holes that are found throughout the body.
Disc
The disc is the part of a butterfly valve that is responsible for controlling flow. It is attached to the valve body and is similar to the structure of a gate in a gate valve. While there are many variations in the design of a disc based on its applications, the common variants include eccentric and concentric.
Seat
The seat is the component of a wave that holds the disc in its place – the seat of a valve is made from strong elastomers to ensure that it does not leave its position. One should also note that the seat is not a small part of the butterfly valve, but rather runs throughout the inner lining of a valve.
Stem
If the butterfly valve is actuated manually, then a mechanism should connect it to the disc so as to throttle it. The stem, or the valve shaft, is the unit that connects the actuation mechanism and the disc. There are two types of stems – wetted and non-wetted.
The working principle of Butterfly valve consisting of a circular disc with a stem in the middle offset, while rotating the actuator, the disc turns either parallel or perpendicular and pressure drop is imparted by the disc even when its open. Butterfly valve belongs to the family of the quarter-turn valve because the disc is rotated in quarter-turn even if it is open or closed. There is a disc on the rod, when the valve is closed the passage is blocked by allowing a quarter turn.
Actuation of Butterfly Valve
Electric
Uses an electric actuator for controlling the valve with a control signal and is typically used for high-precision regulation and time-sensitive applications.
Pneumatic
Also used for high-precision application and uses compressed air for actuation.
Hydraulic
Typically used for applications requiring large torques for opening and closing the valve, such as high-pressure and high-viscosity applications.
Manual
Manually operated butter valves make use of a handwheel, crank, or lever to operate the valve. Smaller manual valves are typically fitted with a lever. For larger sizes, handwheels are provided and are accompanied by a gearbox to transfer the torque with a high mechanical advantage. Another way of manual actuation is in use cases where the valve is buried underground without a manhole; in such applications, actuation is done with an extension spindle, adapter / square cap, and a corresponding T-key from the ground level.
Choose by type
Butterfly valve has different structures such as single eccentric, inclined plate type, centerline type, double eccentric, and triple eccentric. The medium pressure acts on the valve shaft and bearing through the disc, so when the flow resistance of the high-pressure small diameter is large, the shaft diameter and disc thickness will increase accordingly. If a gate valve, ball valve, or globe valve is used, from the aspects of sealing and flow resistance The analysis is more suitable than using a butterfly valve.
Choose according to the sealing structure
The main advantages of metal-sealed butterfly valves are reliable sealing, long life, high-temperature resistance, not ease of damage and tear, and high pressure bearing capacity. Therefore, it has been widely used in recent years, especially for key parts of engineering systems. If the rubber soft sealing butterfly valve is well designed and manufactured, it can get a good seal, and the large diameter is easy to change the ring online. However, rubber has aging problems and can only be used under low-temperature conditions, so it is widely used in tap water and water supply systems.
1. During installation, the valve flap must stay at the closed position.
2. The opening position should be decided according to the rotating angle of the butterfly plate.
3. For those butterfly valves with bypass valves, bypass valves need to be opened before opening the butterfly valves.
4. Installation should be performed according to the manufacturer' s installation manuals. There needs to be a solid foundation for heavy butterfly valves.
Common Butterfly Valve Applications
Food processing
Simple design, high durability, and low maintenance are the features needed to regulate fluid flow in any piping system. Certified Food Grade Seat is best for the Food Processing sector, so a White seat is preferred.
While standard resilient seated valves are not 3A approved, there are many on the market that maintain sanitary connections inside and outside. The body material for the valve can range from Epoxy coated iron to Nylon 11 coated iron to Bronze, 304SS, and 316SS.
Refineries
The butterfly valve is commonly found in refineries. These would typically use the more “high end” High-Performance valve with Steel Bodies, or the Triple Offset design that is “Fire Safe”and bubble tight. Many applications involving water use the resiliently seated version.
Shut off valves
A butterfly valve is often the best choice as a general shut-off valve above 1.5”-148”. Their simple design allows them to take up less space and less weight than other types of valves. These valves provide a tighter seal than a gate of globe valve and are usually bubble tight. This is most useful when trying to stop the fluid flow as it prevents any fluid from passing through the pipe when closed.
Ship building
Because of their high durability in saltwater, butterfly valves are commonly used in ships where ABS-approved materials are selected. This type of valve effectively creates a water-tight shutoff in the piping system of a ship to prevent any flow in the pipe. Their small size also allows them to be used in those tight spaces that are common aboard the ship.
Carbon steel
Carbon steel is an alloy of iron where the main alloying element is carbon. Generally, no other alloying elements are added to control the properties of the material. For butterfly valve construction, carbon steel is most often used to form the body and disc of the valve using the sand casting process.
Carbon steels are available in several different grades. The most common grades used for valve bodies and discs are cast grades ASTM A216 WCB (Weldable Cast B-grade) and LCC (Low Carbon Content) steels. WCB material is most suitable for high temperature use, whereas LCC can be used at low (sub-zero) temperatures.
Stainless steel
The definition of a stainless steel is an alloy of iron with a minimum chromium content of 10.5%. The effect of the chromium is to form a self-healing layer of chromium oxide on the surface of the material. When the surface is broken by mechanical damage such as scratching, the chromium quickly reacts with oxygen in the air, so preventing the oxygen from reacting with the iron and forming iron oxide (rust). An ever-increasing number of stainless steels are available, of which the simple iron-chromium-nickel grades are most often termed 'stainless steel'.
Stainless steels can be further classified as ferritic, austenitic, martensitic, duplex and precipitation hardenable. This classification is based on the microstructure that is developed in the material by varying the alloying elements present. For valve construction, the most common grades used are austenitic and duplex. These are described briefly below.
Austenitic stainless steels
Austenitic stainless steels, in addition to chromium, contain elements such as nickel, which have the effect of retaining the high temperature face-centred-cubic austenitic structure at temperatures where it would normally have transformed to the ferritic body-centred-cubic structure. This face-centred cubic structure gives the material improved toughness and ductility compared to the ferritic grades. Depending on the nickel content, the tough austenitic structure can be retained even at extremely low temperatures, allowing the material to be used in cryogenic applications. Improved resistance to pitting corrosion can be achieved by adding molybdenum to the alloy.
Duplex stainless steels
Duplex stainless steels contain a balanced structure of both the austenitic face-centred cubic and ferritic body-centred structure of iron. This structure is developed by carefully controlling both the alloying elements and the heat treatment performed on the alloy to obtain a structure consisting of 50% austenite and 50% ferrite. The result is an alloy that combines the higher strength of ferrite with the improved toughness of austenite. The super duplex grades contain higher levels of chromium and molybdenum to enhance their resistance to pitting and crevice corrosion.
Nickel alloys
Nickel alloys are used in butterfly valve components where severe service conditions are encountered. These alloys are particularly useful in harsh corrosive environments, which would attack stainless steels by breaking down their protective oxide layer.
Hastelloy nickel-based alloys are most often used in valve construction. There are several different forms of Hastelloy, with each being tailored by adding specific alloying elements is varying proportions to suit particular service conditions.
Titanium alloys
Titanium alloys combine high strength with light weight and excellent corrosion resistance, having the highest strength-to-weight ratio of any metal. In a similar manner to stainless steels, titanium alloys gain their corrosion resistance by the development of a protective oxide layer on its surface. They are particularly resistant to corrosion by seawater, in particular in systems where hypochlorite is present to prevent biofouling.
Nickel aluminium bronze
Nickel aluminium bronze is a copper-based alloy containing approximately 10% aluminium, 5% nickel and 5% iron. The nickel aluminium bronze alloys provide excellent corrosion resistance, particularly in seawater environments. They also strongly resist the formation of a bio-film, which can cause increased corrosion problems in stainless steels.
Installation direction
The butterfly valve installation direction refers to the orientation in which the valve is installed in relation to the flow of the medium.
Horizontal orientation: In most cases, butterfly valves are installed horizontally, meaning the valve's stem is positioned horizontally, and the disc opens and closes in a vertical plane. This orientation allows for easy operation and maintenance as gravity helps to close the valve, and the handle or actuator is easily accessible.
Vertical orientation: Butterfly valves can also be installed vertically, with the stem positioned vertically and the disc opening and closing in a horizontal plane. This orientation may be used when space is limited or the pipeline runs vertically. In this orientation, it's important to consider the flow direction. If the flow is from bottom to top, the valve may close more easily due to the force of gravity. However, if the flow is from top to bottom, the force of gravity may make it harder to close the valve.
Regardless of the orientation, it's important to consider the flow direction, which is usually indicated by an arrow on the valve's body. The valve should always be installed so that the flow of the medium matches this direction. This ensures optimal performance and minimizes wear and tear on the valve. However, if there's a choice, install the valve with the stem horizontally. This distributes the weight of the stem and disc evenly, minimizing seat wear. Moreover, if the media is abrasive, this configuration creates a self-cleaning effect, thereby extending the valve's lifespan.
Installation procedure
Before starting the installation process, it is important to review the manufacturer's instructions carefully. The common steps in installation are:
Positioning: The valve should be properly aligned with the pipe where it will be installed. Ensure that the butterfly disc is open to prevent any damage during installation.
Concentric butterfly valves: Also known as resilient-seated butterfly valves, these valves have a rubber seat and a disc centered in the middle. The installation process involves aligning the valve between two pipe flanges and securing it using bolts. After securing the valve, the disc can be rotated to ensure it doesn't interfere with the valve seat or pipe flanges.
Double offset butterfly valves: Installation of double offset butterfly valves involves careful alignment of the valve in the pipeline to ensure the disc can rotate freely without hitting the pipe flanges. The offset design may require more careful positioning and alignment than a concentric butterfly valve.
Triple offset butterfly valves: Installing a triple offset butterfly valve requires precision to ensure the offsets align correctly with the pipeline. This may require more complex mounting procedures and should be done by trained professionals.
Securing the butterfly valve: Once the valve is positioned, it must be secured. This is typically done by bolting the valve between two pipe flanges. The bolts should be tightened evenly to avoid unnecessary stress or distortion of the valve.
Lugged butterfly valves: Lugged butterfly valves have threaded sockets on both sides of the valve body, allowing them to be installed in a system using two bolt sets without the need for nuts. The valve is positioned between two flanges, with a pair of bolts securing each flange. This design allows either side of the piping system to be disconnected independently without affecting the other side.
Wafer butterfly valves: Wafer butterfly valves are installed by sliding the valve between the flanges on the pipe, then the flanges are tightened onto the valve to hold it in place. This makes them easy to install and disassemble, but they cannot be used when the flow needs to be disrupted.
Connecting the actuator: Attach the handle (for manual valves) or gearbox to the valve. This is usually connected to the top of the valve and must be properly aligned to ensure correct operation.
Testing the butterfly valve: After installing the valve and connecting the actuator, it's essential to test its operation.
Visual inspection: Check the valve for any visible damages. Ensure it is installed correctly.
Operational test: Operate the valve to verify it opens and closes smoothly without any hitches.
Leakage test: With the valve closed, introduce a fluid pressure on one side and check for any leaks.
Functional test: Monitor and verify that the valve works as expected under normal operating conditions.
Performance test: Check for any performance issues such as unusual noises, vibrations, or temperature variations.
Final adjustments: The last step is to make any necessary adjustments. This might include tightening the bolts further, adjusting the positioning of the valve, or fine-tuning the actuator. Once all adjustments are made, the installation process is complete.
SUNAY is a professional manufacturer of valves. Headquartered in Anfeng Industrial Zone, Yongjia, Zhejiang. The company was established in 2010 with a registered capital of 10.8 million yuan and has three holding manufacturing companies. The company’s founder team graduated from mechanical and electrical automation majors and has been engaged in the valve industry for more than 20 years. After years of hard work and development, it has become a key backbone enterprise in the valve industry.
Q: What is butterfly valve used for?
Q: Why use butterfly valve instead of gate valve?
Q: What is the difference between check valve and butterfly valve?
Q: When not to use a butterfly valve?
Q: How do you tell if a butterfly valve is open or closed?
Q: What is a gate valve best used for?
Q: What is the alternative to a butterfly valve?
Q: Which is better gate valve or butterfly valve?
Q: What are the three types of butterfly valves?
Q: Where do you put a butterfly valve?
Q: Why do butterfly valves leak?
Q: Can you install a butterfly valve upside down?
Q: How are butterfly valves installed?
Q: How many turns does it take to open a butterfly valve?
Q: Why is it called a butterfly valve?
Q: Can you repair a butterfly valve?
Q: Is there a flow on a butterfly valve?
Q: How long does a butterfly valve last?
Q: Does butterfly valve prevent backflow?
Q: Should a butterfly valve be vertical or horizontal?
We're well-known as one of the leading butterfly valve manufacturers and suppliers in China. We warmly welcome you to buy or wholesale customized butterfly valve at competitive price from our factory. Contact us for more details.
poly gate valve(0/10)
