Introduction to Butterfly Valves: Understanding the Basics
Butterfly valves are widely favored for controlling fluid flow in pipelines. The simplicity of their design and cost-effectiveness make these valves popular wherever reliable performance is needed on a tight budget. In other words, the butterfly valve operates due to a rotating disc to regulate the liquid or gas flow through a pipe. The disc is set in the valve body to rotate a quarter turn (90 degrees) all the way open or close the passage, providing effective control with minimum effort.
What makes butterfly valves great is their compact size and lightweight constrcution compared to other types of valves. These valves are prized for their efficiency and versatility, and are used in industrial as well as residential setups. Knowing the butterfly valve types will help you make better decisions based on your own needs.
Key Components of Butterfly Valves and Their Functions
For the purpose of understanding the operation of the butterfly valves, it is necessary to know the construction of the valves. All the components are used in a way that the valve should be able to work under various conditions. Here’s a breakdown of the main parts:
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Valve Body: Completely surrounds all internal components and is attached to the pipeline through flanges or a wafer type connection. The material that can be used is stainless steel, ductile iron or carbon steel depending on the need.
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Valve Disc: The component that controls the flow of fluid. Its rotation determines the flow path and provides a high degree of control.
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Valve Seat: Provision of a good seal between the disc and the body to ensure that it will not leak at any one time. These are soft seats for low pressure and metal seats for high temperatures and abrasive service.
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Shaft: Connects the actuator to the disc to enable it rotate the disc.
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Actuation Mechanism: These are the elements that open or close the valve. They are levers, gearboxes or actuators, electrical, pneumatic or hydraulic.
All these elements are incorporated so as to make butterfly valves efficient in many industries and sectors such as pipes, water treatment, and power.
Comprehensive Examination of Butterfly Valve Types
Butterfly valves are widely used in fluid control systems and due to the variety of their types, they can be used in many industries. In this article, we categorize butterfly valves according to the material, actuation, connection, and sealing to help the reader understand the properties, capabilities, and applications of these valves. Below is an expanded table summarizing the classification of types of butterfly valves for your quick reference:
| Classification | Type | Material | Temperature Range | Size Range | Pressure Rating | Cost | Common Applications |
| By Material | Metal Butterfly Valves | Stainless Steel, Carbon Steel, Ductile Iron | -40°C to 650°C (-40°F to 1200°F) | DN50 to DN3000 (2” to 120”) | Up to 40 bar (580 psi) | High | Steam systems, oil and gas pipelines, aggressive media |
| Plastic Butterfly Valves | PVC, Polypropylene | -10°C to 60°C (14°F to 140°F) | DN40 to DN600 (1.5” to 24”) | Up to 16 bar (232 psi) | Low | Water treatment, wastewater, chemical systems | |
| By Actuation | Pneumatic Butterfly Valves | Varies (Metal/Plastic) | Varies (Material Dependent) | DN50 to DN2000 (2” to 80”) | Up to 25 bar (362 psi) | Medium | Process automation in chemical and pharmaceutical industries |
| Electric Butterfly Valves | Varies (Metal/Plastic) | Varies (Material Dependent) | DN50 to DN2000 (2” to 80”) | Up to 16 bar (232 psi) | Medium to High | HVAC systems, power generation, water distribution | |
| Hydraulic Butterfly Valves | Varies (Metal/Plastic) | Varies (Material Dependent) | DN50 to DN3000 (2” to 120”) | Up to 50 bar (725 psi) | High | Oil and gas, high-torque applications | |
| Manual Butterfly Valves | Varies (Metal/Plastic) | Varies (Material Dependent) | DN40 to DN1200 (1.5” to 48”) | Up to 10 bar (145 psi) | Low | Small pipelines, non-critical flow control | |
| By Connection | Flange Butterfly Valves | Stainless Steel, Carbon Steel, Ductile Iron | -40°C to 650°C (-40°F to 1200°F) | DN50 to DN3000 (2” to 120”) | Up to 40 bar (580 psi) | Medium to High | Critical applications like oil and gas processing |
| Wafer Butterfly Valves | Stainless Steel, PVC | -10°C to 120°C (14°F to 248°F) | DN50 to DN1200 (2” to 48”) | Up to 16 bar (232 psi) | Low | Water distribution, low-pressure pipelines | |
| Welded Butterfly Valves | Stainless Steel, Carbon Steel | -40°C to 600°C (-40°F to 1112°F) | DN50 to DN2000 (2” to 80”) | Up to 50 bar (725 psi) | High | High-temperature, high-pressure systems | |
| By Sealing | Soft-Seal Butterfly Valves | Rubber, PTFE | -10°C to 120°C (14°F to 248°F) | DN40 to DN600 (1.5” to 24”) | Up to 16 bar (232 psi) | Low | HVAC, water pipelines, non-aggressive media |
| Hard-Seal Butterfly Valves | Stainless Steel, Graphite | -40°C to 650°C (-40°F to 1200°F) | DN50 to DN3000 (2” to 120”) | Up to 40 bar (580 psi) | High | Steam, petrochemical plants, corrosive/abrasive fluids |
Note:
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Temperature Range and Pressure Rating depend on specific materials and configurations. Refer to butterfly valve manufacturers for precise specifications.
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Cost is categorized as Low (< $100), Medium ($100-$500), and High (> $500) per valve.
Classification by Valve Body Material
Butterfly valves are mainly in two types depending on the material used in the construction of the valve body: the metal and the plastic.
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Metal Butterfly Valves: Valves of this type are made from materials such as stainless steel, carbon steel or even ductile iron and as such are built to handle high pressures and temperatures. They are widely applied in systems where steam, oil or other aggressive media are used. The metallic valves have high mechanical strength and can therefore be effectively used in various industrial settings.
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Plastic Butterfly Valves: Plastic butterfly valves are made from PVC or polypropylene and are lightweight and do not corrode easily and are suitable for use with chemicals, water or wastewater. While they are not as strong as the metallic ones, their low cost and ability to work well in chemical environments makes them suitable for use in low pressure systems.
Classification by Actuation Method
The actuation method refers to the way through which a butterfly valve is operated and may be manual, pneumatic, electric or hydraulic.
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Pneumatic Butterfly Valves: These valves use compressed air to control them and this makes them to work fast and efficient. They are suitable for applications where frequent on and off operations are desired, such as in chemical and pharmaceutical process automation. Pneumatic valves are very reliable in conditions of varying temperature.
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Electric Butterfly Valves: These valves are electric motor operated and are ideal for use in pipelines that require frequent changes in the flow rate due to the ability to control the flow rate accurately. These are commonly employed in power generation, water treatment, and HVAC systems.
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Hydraulic Butterfly Valves: These valves employ the use of liquid pressure to shift the disc and provide high torque for handling with thick or sticky fluids. These are suitable for severe services such as oil and gas pipelines where strong actuation is desired.
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Manual Butterfly Valves: Manual valves are operated by a lever or a handwheel and are relatively simple and economical with low scope for frequent modulation.
Classification by Connection Type
Butterfly valves connect to pipelines in different ways, each method tailored to specific operational demands and providing distinct benefits:
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Flange Butterfly Valves: These valves, designed with integrated flanges, secure to pipe flanges with bolts and gaskets. It features superior flange connection with the ability to maximize stability and alignment, creating further robust seals even under high pressure conditions. Flange butterfly valves are particularly well suited to critical applications in industries such as oil and gas processing, where a tight, vibration resistant seal is critical to safety and efficiency.
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Wafer Butterfly Valves: These valves are installed between two pipeline flanges and are secured with bolts running through the entire assembly. Their small, lightweight design reduces installation time and material costs. Wafer butterfly valves have their limitations, but they are quite useful in low pressure applications such as water distribution systems, where space and easy maintenance are desired.
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Welded Butterfly Valves: These valves are welded directly into the system with a permanent connection to the pipeline, and therefore, do not have to have flanges and bolts. The design of this type of seal provides excellent leak resistance and durability, and is suitable for high temperature or high pressure systems, such as those in power plants. Because of their seamless connection, they require less maintenance and provide reliability in demanding operational environments.
Classification by Sealing Mechanism
Butterfly valve sealing mechanisms are important to the valve’s ability to regulate and secure fluid flow under different operating conditions.
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Soft-Seal Butterfly Valves: The sealing element in these valves is a flexible material such as rubber or PTFE, providing a tight seal and reliable valve with little torque. In low to moderate pressure systems where the media is water, air or other non-corrosive fluids, the soft seal design is particularly effective. This smooth sealing performance reduces the risk of leaks and provides efficiency and operational safety in municipal water pipelines and HVAC systems.
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Hard-Seal Butterfly Valves: These valves are made with metal seats that can rest under high pressures, high temperatures, corrosive or abrasive fluids and then continue to work. In petrochemical plants and steam systems and power generation facilities, in highly demanding industrial environments, this hard seal construction has been proven to excel in providing the resilience required under such extreme conditions. Hard seal butterfly valves are capable of handling aggressive media and high pressure operations and provide long term reliability and durability in the most demanding applications.
Advantages and Disadvantages of Using Butterfly Valves
Due to the design and advantageous functional aspects, butterfly valves are very common in the field of fluid control. Like any component, they also have limitations, however. Below is a breakdown of the key advantages and disadvantages:
Advantages
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Compact Design: Because of their smaller footprint, butterfly valves are a good choice for space constrained installations.
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Lightweight: Lightweight construction reduces strain on pipelines and reduces transportation and installation costs.
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Cost-Effective: In larger sizes, they are generally less expensive than other valve types.
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Quick Operation: Butterfly valves are a simple quarter turn mechanism which allows for rapid opening and closing, thereby improving system responsiveness.
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Versatility: They are available in a wide variety of materials and configurations and can handle a wide variety of media including water, air, chemicals and steam.
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Energy Efficiency: The streamlined valve disc design minimizes pressure loss, thereby reducing energy costs in fluid transport systems.
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Low Maintenance: They use fewer moving parts, and are more affordable to maintain and have a longer service life than butterfly valves.
Disadvantages
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Limited High-Pressure Capabilities: Standard butterfly valves may not operate as well in very high pressure conditions than other alternatives such as ball valves.
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Potential for Leakage: Soft seal butterfly valves will degrade over time, especially in abrasive or corrosive environments, and may leak.
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Flow Disturbance: The disc remains in the flow path even when fully open, potentially causing turbulence and pressure loss.
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Size Limitations: These valves are available in a large range of sizes, but in specific applications, larger valves or more robust valves might be necessary.
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Torque Requirements: Butterfly valves therefore often have to run with higher torque actuators, which complicate and increase the cost of operation in high pressure applications.
The pros and cons of these are understanding. This helps users to make an informed decision and select butterfly valves which are suitable for their system requirements.
Common Applications and Industry Usage of Butterfly Valve Types
Butterfly valves are widely utilized across various industries due to their versatility and reliable performance. Here are some common applications where butterfly valve types are employed:
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Water Treatment
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Power Generation
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Oil & Gas
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Chemical Processing
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Food and Beverage
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HVAC Systems
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Mining
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Pharmaceuticals
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Pulp and Paper
Choosing the Right Butterfly Valve: Key Considerations for Optimal Performance
When something requires us to choose the correct butterfly valve for operation, we cannot afford to get it wrong. Below are the key factors to consider when choosing a butterfly valve:
1. Offset Design
There are different types of offset designs of butterfly valves such as zero offset, single offset, double offset and triple offset butterfly valves. Zero offset designs (also called concentric butterfly valves) are cost effective and simple for low pressure systems. On the other hand, the designs of double offset and triple offset are preferred at extreme temperatures, or for abrasive works as well as high durability applications, since it tends to decrease the friction of the seal ring and prevent the wear of it over time.
2. Seat Material
The seat material chosen shall directly affect the compatibility of the valve with the media being handled. Rubber or PTFE soft materials are best for water or low pressure systems, while metal seats are best for high pressure, high temperature or corrosive environments. For systems using steam, chemicals or other challenging media, this consideration is critical.
3. Connection Type
Tune in to the configuration and the installation of the pipeline. Wafer valves are small and light, and are well suited for systems with limited space. For applications requiring pipeline isolation, lug style valves are the best. In addition, flanged valves seal well for high pressure applications.
4. Actuation Method
The valve can be controlled by any actuation method, manual, pneumatic, electric, or hydraulic. Pneumatic and electric butterfly valves are normally used for automated and precise control. As a trusted maker, Vincer is known for reliable and precise high quality electric and pneumatic actuators for use in demanding industrial applications. If you are interested in Vincer’s products, you may contact us for more information, and professional assistance. Suitable for applications requiring frequent and precise fluid control, these actuators are ideal.
5. Operational Environment
The selection of the valve is influenced by environmental conditions such as temperature, pressure and potential cavitation. Valves with specialized coatings or enhanced materials, like eccentric butterfly valves, can handle harsh conditions and maintain long-term reliability.
Each of these factors should be carefully evaluated in order to choose the proper valve for your system’s particular situation, which increases performance and increases valve longevity. Vincer’s electric and pneumatic butterfly valves provide excellent solutions for modern industrial demands for reliable and precise actuation.
Each of these factors should be carefully evaluated in order to choose the proper valve for your system’s particular situation, which increases performance and increases valve longevity. Vincer’s electric and pneumatic butterfly valves provide excellent solutions for modern industrial demands for reliable and precise actuation.
Final Words
In this article, we covered the kinds of butterfly valves, their use, and a few well considered points for choosing the best valve. There is a variety of options available, from triple offset design to wafer type butterfly valves, each with different advantages depending on a particular requirement.
Vincer is a leader in electric and pneumatic actuated valves for performance and advanced automation solutions you can trust. Contact Vincer today to learn about the perfect valve for your application!