How to Choose the Right Butterfly Valve
Butterfly valves are a type of quarter-turn valve that is commonly used in a wide range of industrial applications. They are named after the butterfly-like shape of their disc, which rotates around a central axis to control the flow of fluid through the valve. Butterfly valves are known for their simplicity, reliability, and cost-effectiveness compared to other types of valves.
However, not all butterfly valves are created equal, and choosing the right one for your specific application is crucial. The wrong butterfly valve can lead to leaks, flow control issues, and even safety hazards. On the other hand, the right butterfly valve can ensure optimal performance, efficiency, and safety in your operation.
This article will discuss the basics of butterfly valves, the factors to consider when choosing a butterfly valve for your application, and specific considerations for several industries including food processing, refineries, shut-off valves, ship building, and other applications. By the end of this article, you will better understand how to choose the right butterfly valve for your needs.
A butterfly valve is a quarter-turn valve that controls the flow of fluid through a pipe by rotating a disc-shaped component in the valve body. The disc is attached to a stem that passes through the center of the disc and is connected to an actuator, which can be manually operated or automated. When the valve is fully open, the disc is perpendicular to the flow of fluid, allowing for maximum flow. When the valve is fully closed, the disc is parallel to the flow of fluid, blocking the flow completely.
A butterfly valve typically consists of the following components:
Body
The main housing of the valve contains the disc, stem, and actuator.
Disc
The disc is the component that rotates within the valve body to control the flow of fluid.
Stem
The stem connects the disc to the actuator and passes through the center of the disc.
Actuator
The actuator is the component that opens and closes the valve. It can be manually operated or automated, depending on the application.
Seat
The seat is the component that provides a tight seal around the disc when the valve is closed.
Bolts
The bolts hold the valve components together and secure the valve to the piping system.
There are three main types of butterfly valves:
Wafer Butterfly Valves
Wafer butterfly valves are designed to fit between two flanges and are held in place by bolts that pass through the valve body and the flanges. They are the most common type of butterfly valve and are suitable for various applications, such as HVAC systems, pharmaceutical processing, food processing, water treatment plants, or chemical processing.
Lug Butterfly Valves
Lug butterfly valves have threaded inserts on either side of the valve body that allow them to be bolted to the pipe. They are often used in applications where the valve needs to be easily removed from the piping system for maintenance or replacement.
Flanged Butterfly Valves
Flanged butterfly valves have flanges on either side of the valve body that allow them to be bolted directly to the pipe. They are suitable for applications where high-pressure or high-temperature fluids are being transported.
When choosing a butterfly valve for your application, it is important to consider several factors to ensure optimal performance, efficiency, and safety. The following are some of the key factors to consider:
The fluid transported through the valve will have a significant impact on the type of butterfly valve that is suitable for the application. Factors to consider include:
Temperature
The fluid’s temperature can affect the construction material, as some materials may not be suitable for high-temperature applications.
Pressure
The pressure of the fluid can impact the design of the valve, as higher pressure applications may require a stronger valve construction.
Viscosity
The fluid’s viscosity can affect the flow rate and the valve size required.
Corrosiveness
If the fluid is corrosive, the valve material must resist corrosion.
The specific application will also influence the type of butterfly valve required. Factors to consider include:
Industry
Different industries have different requirements for butterfly valves. For example, food processing applications may require valves that are easy to clean and have sanitary designs.
Function
The function of the valve (e.g., shut off, throttling) will determine the type of valve required.
Location
The valve’s location (e.g., above or below ground) will impact the design and construction.
The required valve size will depend on the flow rate and pressure of the transported fluid. Therefore, choosing the right valve size is important to ensure optimal performance and prevent issues such as flow restriction or leakage.
The material of construction impacts one’s choice in that different materials are better suited for different fluid characteristics and applications. Common materials for butterfly valves include stainless steel, PVC, and cast iron.
Stainless Steel
Stainless steel is highly durable and corrosion-resistant, making it ideal for use in applications with harsh chemicals, high temperatures, and corrosive environments, such as in the chemical processing, food and beverage, and pharmaceutical industries. Stainless steel also has a smooth surface finish, making it easy to clean and maintain, which is important in industries where cleanliness and hygiene are critical.
PVC
PVC (polyvinyl chloride) is a lightweight and cost-effective material commonly used in applications with low-pressure and low-temperature requirements, such as in water treatment plants and swimming pool systems. PVC is resistant to chemical corrosion and easy to install and maintain.
Cast Iron
Cast iron is a durable and long-lasting material commonly used in applications with high pressures and temperatures, such as in the oil and gas industry. Cast iron is also relatively inexpensive compared to other materials, making it a cost-effective choice for applications where cost is a significant factor.
The cost of the valve will depend on the type of valve required, the construction material, and the valve’s size. Therefore, balancing cost considerations with the required performance and safety features is important.
Environmental and safety regulations may dictate the type of valve required. For example, valves used in the food industry may need to meet FDA and USDA requirements for food safety. In contrast, valves used in high-pressure applications may need to comply with specific safety standards.
Butterfly valves are widely used in the food processing industry due to their sanitary design and ease of cleaning. However, when choosing butterfly valves for food processing applications, there are some specific considerations to keep in mind.
Special Considerations
Sanitary Design
Butterfly valves used in food processing applications must be designed to prevent bacterial growth and contamination. Valves with smooth, crevice-free surfaces are easier to clean and less likely to harbor bacteria.
Clean-in-Place (CIP) and Sterilize-in-Place (SIP) Compatibility
CIP and SIP systems are commonly used in food processing plants to clean and sanitize equipment without disassembly. Butterfly valves used in these applications must be compatible with these systems and withstand the chemicals used in the cleaning process.
Traceability
Traceability is important for identifying the source of food contamination in the event of a recall. To ensure food safety and quality control, butterfly valves used in food processing applications should be traceable.
Materials
Stainless Steel
Stainless steel is the most common material used for food-grade butterfly valves due to its corrosion resistance, durability, and ease of cleaning.
PVC
PVC is also commonly used for food-grade butterfly valves due to its low cost and ease of installation. However, it is not suitable for high-temperature applications.
Other Materials
Other materials used for food-grade butterfly valves include brass, bronze, and aluminum. However, these materials may not be suitable for all food processing applications.
Regulations & Requirements
FDA
Butterfly valves used in food processing applications in the United States must meet FDA requirements for food contact materials.
USDA
Butterfly valves used in meat and poultry processing applications must meet USDA requirements for food contact materials.
3A Sanitary Standards
The 3A Sanitary Standards organization provides guidelines for designing, constructing, and installing equipment used in the food processing industry.
European Hygienic Engineering and Design Group (EHEDG)
The EHEDG provides guidelines for hygienic engineering and the design of equipment used in the food processing industry in Europe.
Butterfly valves are commonly used in the refining industry due to their ability to handle a wide range of pressures and temperatures. However, when choosing butterfly valves for refinery applications, there are some specific considerations to consider.
Special Considerations
High Temperatures and Pressures
Refinery applications often involve high temperatures and pressures, so butterfly valves used in these applications must be able to withstand these conditions.
Corrosive Environments
Refinery environments can be highly corrosive, so butterfly valves used in these applications must resist corrosion.
Fire-Safe Design
In refinery applications, butterfly valves may require fire-safe design features to prevent the spread of fire.
Materials
Carbon Steel
Carbon steel is a common material used for butterfly valves in refinery applications due to its high strength and resistance to corrosion.
Stainless Steel
Stainless steel is also commonly used for butterfly valves in refinery applications due to its high resistance to corrosion and high temperatures.
Alloy Steel
Alloy steel is used for butterfly valves in applications that require even higher strength and resistance to corrosion than carbon or stainless steel.
Regulations and Requirements
API Standards
The American Petroleum Institute (API) provides standards for butterfly valves used in the refining industry, including API 609 and API 598.
API 609: Butterfly Valves: Double Flanged, Lug- and Wafer-Type
Specifies the requirements for design, materials, manufacturing, testing, inspection, and marking of double-flanged, lug- and wafer-type butterfly valves. This standard applies to butterfly valves used in petroleum, petrochemical, and gas industry applications.
API 598: Valve Inspection and Testing
Provides guidelines for inspecting and testing industrial valves, including butterfly valves, to ensure their proper operation and performance. This standard outlines the testing requirements, including hydrostatic shell testing, seat leakage testing, and other applicable testing methods.
NACE Standards
The National Association of Corrosion Engineers (NACE) provides standards for materials used in corrosive environments, including butterfly valves used in refineries.
ASME Standards
The American Society of Mechanical Engineers (ASME) provides standards for the design and construction of pressure vessels and piping used in refineries. Butterfly valves used in these applications must comply with these standards.
Safety Regulations
Besides industry standards, butterfly valves used in refinery applications must comply with safety regulations, including those set by the Occupational Safety and Health Administration (OSHA).
One example of the Occupational Safety and Health Administration (OSHA) regulating butterfly valves is the requirement for properly guarding the valve handles to prevent accidental operation. According to OSHA’s Standard for Control of Hazardous Energy (Lockout/Tagout), control valves, including butterfly valves, must be properly guarded or de-energized before maintenance or servicing activities are performed.
Butterfly valves are commonly used in ship building applications due to their compact design, easy operation, and ability to handle a wide range of fluids. However, when choosing butterfly valves for ship building applications, there are some specific considerations to keep in mind.
Special Considerations
Saltwater Environment
Ship building applications involve exposure to saltwater, so butterfly valves used in these applications must resist corrosion.
Vibration and Shock
Ship building applications involve high levels of vibration and shock, so butterfly valves used in these applications must be able to withstand these conditions.
Space Constraints
Ship building applications involve limited space, so butterfly valves used in these applications must be compact in design.
Materials
Bronze
Bronze is a common material used for butterfly valves in ship building applications due to its high resistance to corrosion in saltwater environments.
Stainless Steel
Stainless steel is also commonly used for butterfly valves in ship building applications due to its high resistance to corrosion and strength.
Other Materials
Other materials used for butterfly valves in ship building applications include aluminum bronze, nickel, aluminum bronze, and titanium.
Regulations and Requirements
International Standards
Butterfly valves used in ship building applications must comply with international standards, such as those set by the International Maritime Organization (IMO).
The International Maritime Organization (IMO) provides regulations and guidelines for the safe operation of ships and the prevention of marine pollution. One example of the IMO regulating butterfly valves is the requirement for marine-grade butterfly valves in certain applications on board ships.
Classification Societies
Classification societies, such as Lloyd’s Register and the American Bureau of Shipping, provide regulations and requirements for butterfly valves used in ship building applications.
The American Bureau of Shipping (ABS) provides classification and certification services for ships and offshore structures, including inspecting and testing various equipment and components used in these applications. While ABS does not specifically regulate butterfly valves, it does guide the design, construction, and installation of these valves for use in marine applications.
Safety Regulations
Besides industry standards, butterfly valves used in ship building applications must comply with safety regulations, including those set by the International Convention for the Safety of Life at Sea (SOLAS).
The Safety of Life at Sea (SOLAS) is an international convention that sets minimum safety standards for ships, including safety equipment and procedures. While SOLAS does not specifically regulate butterfly valves, it does provide requirements and guidelines for the safety and reliability of shipboard equipment, including valves.
Butterfly valves can be a good choice for ship building applications due to their compact design, easy operation, and ability to handle a wide range of fluids. However, the specific operating conditions of the application and the relevant regulations and requirements must be considered when choosing butterfly valves for ship building applications.
Butterfly valves can be used as shut-off valves in many applications due to their ability to quickly and easily control flow. However, when choosing butterfly valves as shut-off valves, there are some specific considerations to keep in mind.
Special Considerations
Tight Shut-Off
When used as shut-off valves, butterfly valves must provide tight shut-off to prevent leakage.
Pressure and Temperature
The butterfly valves used as shut-off valves must be able to withstand the pressure and temperature of the application.
Operating Conditions
The application’s operating conditions, such as the frequency of operation, must also be considered when choosing butterfly valves as shut-off valves.
Benefits and Drawbacks
Benefits
Butterfly valves used as shut-off valves offer several benefits, including low cost, low torque operation, and the ability to handle a wide range of flow rates.
Drawbacks
However, butterfly valves used as shut-off valves may have some drawbacks, including the potential for cavitation and erosion and a limited range of operating pressures and temperatures.
Applications
Water and Wastewater Treatment
Butterfly valves are commonly used as shut-off valves in water and wastewater treatment applications due to their low cost and ease of maintenance.
HVAC Systems
Butterfly valves are also commonly used as shut-off valves in heating, ventilation, and air conditioning (HVAC) systems due to their low torque operation and ability to handle a wide range of flow rates.
Process Control
Butterfly valves can be used as shut-off valves in many process control applications, such as those in the chemical and pharmaceutical industries.
Overall, butterfly valves can be a good choice for shut-off valve applications that require low cost, low torque operation, and the ability to handle a wide range of flow rates. However, the specific operating conditions of the application must be considered when choosing butterfly valves as shut-off valves.
Butterfly valves are used in a wide range of industries and applications beyond food processing, refineries, shut-off valves, and ship building. Some examples of other industries and applications where butterfly valves are commonly used include HVAC systems, water treatment plants, chemical processing, and power generation. When choosing butterfly valves for these applications, there are some specific considerations to keep in mind.
HVAC Systems
Butterfly valves are commonly used in HVAC systems to regulate air and water flow. When choosing butterfly valves for HVAC applications, it is important to consider factors such as size, temperature range, and sealing requirements
Water Treatment Plants
Butterfly valves are commonly used in water treatment plants to regulate water flow and chemicals. When choosing butterfly valves for water treatment applications, it is important to consider factors such as corrosion resistance, material compatibility, and pressure ratings.
Chemical Processing
Butterfly valves are commonly used in chemical processing applications to regulate the flow of chemicals. When choosing butterfly valves for chemical processing applications, it is important to consider factors such as material compatibility, corrosion resistance, and temperature range.
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Power Generation
Butterfly valves are commonly used in power generation applications to regulate the flow of steam and other fluids. When choosing butterfly valves for power generation applications, it is important to consider factors such as corrosion resistance, temperature range, and pressure ratings.
In addition to these few examples, butterfly valves are versatile and can be used in various industries and applications. However, when choosing butterfly valves for specific applications, it is important to consider the application’s operating conditions and requirements to ensure that the selected valve is appropriate for the task.
Butterfly valves are essential in nearly all industrial applications due to their effectiveness in isolating system flow. Thanks to their small size, adaptability, and affordability, they are the go-to option in every industry. Choosing the correct butterfly valve for your system can be challenging due to the wide range of alternatives available, including material, size, actuation and construction design.
This article will help you learn about the many varieties of butterfly valves, their technical specs, and the most important things to know about their maintenance. Wafer, lugged, double-flanged, zero-offset, double-offset, and triple-offset butterfly valves are among the many varieties covered. The actuation and material-based classification of butterfly valves will also be covered. Using this information, you can select the best value for your setup.
A butterfly valve is a quarter-turn valve that isolates the flow of liquids, gases, or slurries via a pipe. It rotates a disc (the closure element) around a central axis perpendicular to the flow direction. When the disc is parallel to the flow, the valve opens; when it is perpendicular, it closes.
No matter which type of butterfly valve you are going to install, the basic working principle is the same. The operation of a butterfly valve relies on the precise rotation of its disc to control fluid flow. Don’t worry; you will learn about what a disc is and other components in the following section.
The valve opens when the disc is parallel to the flow. This way it allows maximum flow through the piping or system. On the other hand, when the disc is rotated to a perpendicular orientation, such as shown in the figure below, the valve enters the closing position. Once it is closed, it will block any passage through the system. Additionally, adjusting the disc to intermediate angles allows the valve to regulate the flow rate to some degree. This provides versatile control of anything flowing through to meet varying operational requirements.
Now, let us guide you about the main components of any butterfly valve. It comprises five core components working together to isolate flow effectively. As you can see in the image, the disc is at its core. This disc was mentioned above in the rotated working principle to regulate fluid passage. Then comes the seat. A seat is like a sealant that provides a sealing surface for the disc to sit or rest in a closing position. It is necessary for a tight closure of the passage. Like any component, both parts need a housing called the body. It also connects the valve to the pipeline. Then comes the stem, as you see. It is seen as a tiny rod connected to the disc. It serves as the linkage between the disc and the actuator.
The actuator can be a manual lever, pneumatic, or electrical. Then comes the stem, which is an essential part of the valve that transmits the rotational motion from the actuator to open and close the valve and adjust its position. The actuator is the mechanism that rotates the stem and disc to adjust the flow as required.
The butterfly valves come in various configurations, materials, actuation types, and construction designs. It is essential to learn about each to understand which one will be suitable for your applications. Process Systems has stock of butterfly valves that meet all your industrial needs. Each valve is quality-checked and designed to suit your specific applications and pressure/temperature-based performance requirements. The types of butterfly valves are classified based on various factors, such as shown in the image below.
The good point is that we have all the types of valves to serve your application needs. Let us now discuss the most important ones so that you can understand them in more detail.
If you’re looking for a compact, lightweight valve that easily fits into tight spaces, a Wafer Butterfly Valve could be an excellent choice for your system.
With a thin body design, you can sandwich it between two flanges using bolts. Moreover, it relies on a single rubber or elastomeric seat for sealing. With these features, it is suitable for medium pressures generally up to 16 Bar. This feature makes it highly effective in HVAC systems, water distribution, and other low-pressure industrial processes.
This butterfly valve is engineered with a ductile iron body (1), coated with a fusion-bonded epoxy, for robust structural strength and superior corrosion resistance. The disc (4) is constructed with CF8M to ensure durability and reliable sealing, while the shaft (3) is manufactured with SS431. SS431 delivers high-strength torque transmission. The EPDM seat (2) provides dependable sealing against fluids, while the PTFE bushing (5) reduces friction for smooth operation. An NBR O-ring (6) enhances leak resistance, and the handle (7), manufactured with ductile iron, offers reliable control. Additional components include a circlip (8) made from SS316 for secure assembly, an SS304 card (9) added for more structural integrity, and A2 – 70 bolts and nuts (10) for corrosion-resistant fastening. These high-quality materials ensure the valve’s long-lasting, efficient performance in demanding applications.
Along with this High-Pressure Wafer Ductile Iron Butterfly Valve, we also have a stock of UPVC Double-Acting Pneumatic Wafer Butterfly Valves and UPVC Spring-Return Pneumatic Wafer Butterfly Valves.
One key benefit is its ease of installation and removal. Its slim profile also keeps costs down. However, its sealing capabilities are somewhat limited so that it wouldn’t be suitable for high-pressure or high-temperature scenarios.
Lugged butterfly valves feature threaded inserts commonly called “lugs.” These lugs allow you to bolt them directly to multiple flanges. This design lets you remove or maintain one side of your pipeline without disturbing the other. You can choose to offer partial isolation when you need it most.
At Process Systems, lugged valves are available in sizes ranging from 50mm to 600mm. All sizes have an FBE-coated ductile iron body that delivers durability and corrosion resistance. An EPDM seat provides reliable sealing performance. We have built it with 316 stainless steel discs so that it can work best under challenging conditions.
This valve is built around a ductile iron body (FBE coated) in accordance with AS-7 and ASTM A536. These standards assure structural integrity and corrosion resistance. The EPDM seat (70 IRHD) ensures a reliable seal, while the stainless-steel shaft (SS431, per ASTM A370) and disc (CF8M, also per ASTM A370) deliver strength and durability. A polymer PTFE bushing reduces friction, complemented by an NBR O-ring (70 IRHD) to enhance leak-tight performance.
One of the standout advantages you’ll notice is the valve’s ability to isolate a section of your pipeline for maintenance without disrupting the entire system. This feature makes these valves appropriate if your operation demands frequent inspections or part replacements.
These valves will do the same pressure as their wafer cousins but allow outfall applications (where the valve will be bolted). Lugged butterfly valves tend to be heavier and bulkier than wafer types, which can increase the associated cost a little. If you’re on a tight budget or weight is a critical factor, you’ll want to balance these considerations. Now, let’s learn about the common applications of lugged valves.
Lugged butterfly valves are preferable in industrial pipelines requiring routine or segment-by-segment maintenance. At Process Systems, we have a Lugged Ductile Iron Butterfly Valve, Lugged Ductile Iron Spring Return Butterfly Valve, and Lugged Ductile Iron Double Acting Butterfly Valve, with a 316 S.S disc and an EPDM seat. This make these valves suitable to a wide range of general water applications.
These can be actuated by either a lockable lever and notch plate or gearbox. The unique bonded cartridge design gives them a longer life span. It allows the vacuum to be run through them and makes them replaceable if the need arises. Common applications of these valves include water trucks, irrigation systems, cement hoppers, and other industrial applications.
Moreover, these valves are certified by Watermark, Standards Mark, and WSAA (Water Service Association of Australia). If you need a size above 600mm, you will need to use double-flanged valves. You'll appreciate these valves' convenience if you frequently need to shut down just one part of your system to perform repairs or upgrades.
Double-flanged butterfly valves are engineered with flanges on the inlet and outlet ends. This characteristic provides a leakproof sealing to the pipelines. Moreover, these extended mounting surfaces allow for straightforward installation and facilitate higher pressure ratings up to ANSI 300–. This is the reason they are used reliably for demanding flow control applications.
We have designed the double-flanged valves to suit AS PN16. Depending on the size, you can use them for various pressure considerations. The size variations can range from 50 mm to mm, offering flexibility across various industrial processes.
The valve body is made of ductile iron (AS-7, ASTM A536) and coated with Fusion Bonded Epoxy (FBE), which provides exceptional corrosion resistance and durability. The EPDM seat (Watermark approved) ensures a tight seal against fluid leakage. Along with that, the CF8M stainless steel disc (ASTM A370) delivers high performance in corrosive or high-pressure environments. To improve operational integrity, the valve has upper and lower shafts made of SS431 stainless steel (ASTM A370), as well as a stainless-steel pin (SS316, ASTM A370) for added strength. However, to avoid potential failure points, polymers are employed in the bushing to minimize friction, and an NBR O-ring adds sealing reinforcement.
When it comes to actuation, these valves can be fitted with either a lockable lever and notch plate or an IP67-rated gearbox featuring a stainless-steel shaft and a clear visual indicator. These options allow operators to select the most suitable control mechanism for their application requirements. Moreover, we have Double Flanged Electric Butterfly Valve, Double Flanged Spring Return Butterfly Valve (Flanged AS PN16) and Double Flanged Double Acting Butterfly Valve (Flanged AS PN16).
In high-pressure applications, sealing the seals is a significant challenge to overcome. So, the design of these valves, based on precision engineering principles, delivers superior sealing capabilities and reduces leakage risks. However, the additional materials and dual flanges make double-flanged butterfly valves heavier and costlier than single-flanged or wafer-style valves. Despite the higher upfront investment, they excel in applications where reliability, partial or full isolation, and longevity are paramount.
Comparison of Different Types of Butterfly ValvesFeature
Wafer
Lugged
Double Flanged
Double Offset
Triple Offset
Construction
Thin body, single flange
Reinforced body, multiple lugs
Two flanges, robust body
Dual-offset mechanism
Triple-offset mechanism
Installation
Between two flanges
Bolted via lugs
Bolted between flanges
Flanged or lugged mounting
Flanged mounting
Sealing
Single elastomeric seat
Single/double seats
Double seats
Metal-to-metal, dual seats (RTFE)
Advanced metal-to-metal seals (Stellite)
Pressure Rating
Vacuum to 16 Bar
Vacuum to 16 Bar
0 to 16 Bar
Up to 20 Bar
Up to 20 Bar
Temperature Range
-20 to 130°C
-20°C to 90°C
-20°C to 90°C
-29°C to 180°C
0°C to 400°C
Applications
HVAC, water systems
Industrial pipelines
High-pressure systems
High-pressure, throttling
Extreme conditions, zero leakage
Advantages
Lightweight, compact
Flexible installation
Superior sealing
Reduced wear, reliable sealing
Zero leakage, extreme durability
Disadvantages
Limited sealing
Heavier, costlier
Bulkier, more expensive
More complex than standard types
More expensive, complex
The construction and versatile design of double-flanged valves minimize downtime by ensuring dependable operation, even under challenging conditions. Whether you need to manage aggressive fluids, high-pressure flows, or critical shutoff scenarios, these valves offer a durable and customizable solution for long-term performance.
Now, you will learn about the classification of butterfly valves based on the position of the disc in relation to the centre. This is usually called offset, and it comes in three different offset positions: zero offset, double offset and triple offset.
These are the butterfly valves commonly used in industrial applications. The disc and stem of zero-offset butterfly valves are positioned at the center of the valve seat, which is aligned with the center of the valve body. The disc rotates around a central axis, enabling a full 360° rotation. Sealing is achieved as the disc compresses the soft seat, generating friction throughout the operating cycle.
These valves are widely used in liquid and gas systems with pressures up to 16 Bar and temperatures reaching 90°C (higher with other seat materials). They are well-suited for applications involving food products, coatings, chemicals, abrasives, and solid materials. One significant advantage of zero-offset valves is that the flowing medium does not come into contact with the valve body, as the valve seat provides complete coverage and protection.
The double-offset butterfly valve, often called a high-performance butterfly valve, features two key offsets relative to the valve body’s center. The first one is the shaft axis, which is offset from the centerline of the disc’s seat and the body seal. The other one is in which the shaft axis is eccentric to the centerline of the valve and pipeline.
This design positions the disc so that it creates a cam-like action during operation. As the valve opens or closes, the seat lifts off the seal, minimizing friction except during the initial 10° and final 10° of the opening and closing cycles.
Double-offset butterfly valves are ideal for applications requiring higher pressure handling than zero-offset butterfly valves can accommodate. Their design and durability make them suitable for more demanding operational conditions.
The triple-offset butterfly valve incorporates three offsets, like those in a double-offset butterfly valve. The third offset, however, is in the geometry of the valve’s seating surface rather than the shaft position.
In this design, the sealing components are precision-machined to form a conical profile on the valve seat and disc. This ensures that the disc only contacts the seat during the first and last 1° of the opening and closing cycles, significantly reducing wear and friction.
Triple-offset butterfly valves are suitable for applications similar to double-offset valves but excel in tighter and more demanding environments. Their precise design makes them ideal for high-pressure, high-temperature, and critical sealing applications.
Butterfly valves, available on the market, are made of different materials, including stainless steel, ductile iron, Carbon Steel, and UV-stabilised PVC. The material selection of different components of these valves also varies to make them suitable for different industrial applications.
Stainless steel is commonly used for the body because it is corrosion-resistant, making it ideal for aggressive media. Ductile iron is another material for the body, offering a cost-effective solution for water and gas applications. Moreover, a plastic polymer body is also available for lighter applications. Carbon steel, which is known for its high strength, is typically employed in high-pressure environments.
The disc can be made from stainless steel for its corrosion resistance, PVC/CPVC for non-aggressive fluid handling, or composite materials for lightweight and corrosion-resistant performance.
The seat materials vary based on the application, with rubber or elastomers offering flexible sealing in low-pressure settings, PTFE and EPDM (Teflon) providing excellent chemical resistance and high-temperature tolerance, and graphite being used for applications requiring high-temperature endurance.
All the mechanical equipment, wear, tear, and maintenance for issues also occur in butterfly valves. Understanding and troubleshooting the issue is half solved. Conversely, solving an issue that doesn’t exist only adds to the costs. We have listed some common issues in the table below that can serve as reference points for checking your valves. If you are confused or unsure, you can contact our customer support team, and we will provide you with details.
Common Issues and their solutions in butterfly valvesSeveral key factors influence the selection of materials for butterfly valves to ensure optimal performance and durability in various applications. Corrosion resistance is critical for handling aggressive or corrosive fluids, preventing material degradation, and ensuring long-term reliability. Temperature tolerance is equally important, as materials must withstand the operating temperatures of the system, particularly in high-temperature processes, without compromising structural integrity. Additionally, the material’s strength must match the system’s pressure requirements to handle varying pressure conditions safely and effectively. Lastly, media compatibility is essential to prevent adverse reactions between the material and the fluid being handled, ensuring the valve’s integrity and avoiding contamination or damage to the system.
As now you have learned the details about the most commonly used butterfly valves, you see that these butterfly valves are indispensable components. Due to their compact design, versatility, and cost-effectiveness, they are the best choice to control the flow in the system. You can now select the type of valve suitable for your application based on your understanding of the different types, such as a wafer, lugged, double-flanged, zero-offset, double-offset, and triple-offset butterfly valves. You can maintain the highest possible efficiency with durability by choosing the appropriate valve based on your pressure, temperature, and control mechanism. Moreover, proper material selection will help save not only your cost but also your durability. You can install the stainless-steel valve where needed instead of a UPVC one or vice versa. These technical decisions affect factors like corrosion resistance, temperature tolerance, and media compatibility, ensuring durability and reliability in diverse applications. Not all of this, but the awareness of common issues and their solutions will help you in optimum maintenance of the valve’s performance and minimize downtime, which will extend its service life.
Contact us to discuss your requirements of Butterfly Damper Valve SAF11. Our experienced sales team can help you identify the options that best suit your needs.