Butterfly valves are key to handling of dry bulk materials across a variety of industrial applications. Their design enables efficient handling of fine to coarse dry materials in systems relying on gravity discharge or pneumatic transfer. These valves are installed at the discharge point of storage vessels such as silos, hoppers, and bins, or integrated with chutes or conveyor systems. Their simplicity, reliability, and compact profile make them a preferred choice for both manual and automated flow control in industries like food processing, plastics, cement, chemicals, and agriculture.
Butterfly valves operate using a disc, either flat or slightly curved, mounted on a shaft that rotates within a circular casing. This rotating action allows the valve to open and close efficiently, controlling the flow of bulk material. When the valve is opened, the disc turns to a position parallel to the direction of flow, creating an unobstructed path for bulk material to pass through with minimal resistance. It is especially suitable for handling materials that move easily under gravity or are conveyed pneumatically. The design ensures fast operation and helps maintain a consistent flow rate, reducing the risk of clogging or bridging that can occur in more complex valve types.
When closed, the disc rotates into a perpendicular position, locking tightly against a soft-sealing seat to block material flow. This shut-off capability is essential in preventing material leakage and controlling material flow in processing systems. Heavy-duty versions of butterfly valves are engineered to withstand the pressure and abrasion of high-velocity pneumatic conveying lines, equipped with reinforced bodies and wear-resistant components. Optional features such as air actuators, limit switches, and position indicators can further enhance their functionality, making them an integral part of modern bulk material handling systems.
Butterfly Valve Types
• Double Flanged Butterfly Valves:
These valves are equipped with bolted flanges on both ends, providing a robust and secure connection to the connected pipeline or equipment. This design ensures excellent stability and alignment, making them ideal for heavy-duty, and other bulk material handling systems where a strong, leak-proof connection is essential.
• Single Flanged Butterfly Valves:
Equipped with a bolted flange on one side, these valves offer flexibility in installation. The opposite end is designed with a short built-in pipe, which allows for the attachment of a flexible sleeve or connector. This configuration is especially useful in systems where a rigid flange connection is needed on one side, while the other side requires adaptability to accommodate vibration, misalignment, or thermal expansion.
• Wafer Type Butterfly Valves:
Wafer type valves are designed to fit between two pipe flanges, fastened securely by the flange bolts. This compact arrangement reduces weight and space requirements while maintaining a reliable seal. The valve’s faces are lined with rubber or elastomeric seals on both sides, which compress against the flanges to prevent leaks. This design is widely used in piping systems where ease of installation and maintenance, as well as cost-effectiveness, are demanded.
Design Features and Benefits of Butterfly Valves
• Suitable for Various Bulk Materials:
Designed to handle a wide range of dry bulk materials including powders, granules, flakes, and pellets, these butterfly valves ensure smooth and reliable flow control across diverse material types widely used in industrial processes.
• Compact Low-Profile Design:
The valve body features a low-profile construction that minimizes the flange-to-flange height, allowing for easier installation in tight spaces and minimizing the space required while maintaining full functionality.
• Flexible Installation Options:
Butterfly valves are designed to fit both new installations and system enhancements, offering versatile solutions for existing or new bulk handling systems.
• Optimized Disc and Seal Material Selection:
Careful selection of the butterfly disc and sealing materials ensures consistent, efficient operation by minimizing wear and preventing leaks.
• Actuation During Material Flow:
Butterfly valves can be operated while material is actively flowing under gravity, allowing precise control of discharge rates without interrupting production or risking blockages.
• Compatible with Standard Flanges:
Available with industry-standard DIN or ANSI flange configurations, butterfly valves can be easily integrated into existing piping systems worldwide, ensuring compatibility and simplifying installation.
• Material Options for Durability and Application Needs:
Cast steel and cast aluminum valve bodies are offered to meet different strength, weight, and corrosion resistance requirements, allowing selection based on the specific demands of the application.
• Specialized Stainless Steel and Food-Grade Models:
For sanitary or food processing environments, stainless steel and food-grade butterfly valves comply with hygiene standards and prevent corrosion, making them suitable for sensitive product handling.
• High-Temperature Resistance:
Certain models are designed to operate reliably at temperatures up to 250°C, making them ideal for gravity discharge of bulk solids in high-temperature industrial processes.
• Multiple Actuation Methods:
Butterfly valves can be operated manually via hand levers or automatically using pneumatic actuators, pneumatic pistons, or electric drives, offering flexible control options to match operational needs.
• Integrated Position Monitoring:
Many valves come equipped with built-in limit switches and position indicators, enabling real-time monitoring of valve status for improved process control and safety.
• Custom-Engineered Solutions:
Slide gate valves can be tailored to suit challenging applications, with options for unique dimensions, construction materials, and performance specifications.
• ATEX-Certified Models for Hazardous Areas:
For environments with explosive or hazardous atmospheres, ATEX-certified butterfly valves ensure safe and compliant operation, providing safety in high-risk industrial settings.
Butterfly Valve Application Examples
• Silo Discharge Butterfly Valves:
Butterfly valves are generally equipped with pneumatic actuators that allow for automated opening and closing of the valve, enabling precise control over the discharge of materials from silos. By regulating the flow, they help maintain consistent feeding rates to downstream equipment such as conveyors or feeders. Their automation reduces manual intervention, improving operational efficiency and safety in bulk material handling processes.
• Manually Operated Butterfly Valves:
Typically installed under silos or hoppers, these valves serve as isolation points for equipment maintenance, such as rotary valves or screw feeders located downstream. Manual operation allows operators to quickly shut off material flow during inspections, repairs, or cleaning procedures, ensuring safe working conditions. This type of valve provides a reliable, efficient solution where automated control is not required.
• Dry Bulk Mixers:
Installed at both the inlet and outlet of dry bulk mixers, butterfly valves regulate the movement of bulk solids entering and leaving the mixing area. At the inlet point, the valve controls the introduction of powdered or granular ingredients, ensuring proper dosing and preventing backflow. After mixing, the valve regulates the discharge of the blended product, facilitating smooth transfer to the next stage of processing or packaging.
These valves are typically actuated by pneumatic actuators and are used to automatically open and close the product flow to discharge material to downstream equipment.
Installed below silos or hoppers, these valves are used for maintenance operations of equipment such as rotary valves, screw feeders, etc., that are positioned below the butterfly valve.
These valves are typically actuated by pneumatic actuators and are used to automatically open and close the product flow to discharge material to downstream equipment.
In this design, the butterfly valve is sandwiched between two flanges. Rubber sealing at both faces of the valve provides a tight seal between the flanges and the wafer butterfly valve.
One side of the valve has a bolted flange connection, while the other side features a built-in short pipe designed for fixing a flexible sleeve.
These valves have bolted flange connections on both sides, making them suitable for installation on silos, hoppers, screw feeders, and similar applications.
Bulk tanker trucks or open trucks can be filled with powdered materials delivered within FIBC bags. These systems generally consist of bulk bag discharging station, mechanical or pneumatic conveyor and loading bellow. Big bag discharge station transfers the bulk solid from big bag to conveying system. Conveying system transfers it to truck loading area. And loading bellow is used to fill tanker truck without any dust emission. Since truck loading operations are done within limited time, high capacity big bag discharge systems and bulk material conveying systems are used. For short distances, screw conveyors are preferred to transfer material from big bag discharge station to truck loading chute. For long conveying distances, pneumatic conveying systems provide better service. There may exist a storage hopper or silo above bulk truck loading bellow to compensate material flow between inlet and outlet. Bulk bag discharge and truck filling systems have automatic control system that monitors product level in truck and operates all equipment accordingly. Optional weighing system can be added to measure the amount of material that is filled to truck.
Big bag discharge systems can deliver dry bulk solids in powder and granular form to weighing and batching systems. The loading hopper of the weighing system should remain full during dosing and batching. Big bag discharge systems can monitor the product level in the loading hopper and maintain a constant level automatically. Depending on the dosing speed and conveying distance, mechanical conveying systems or pneumatic loading systems may be used. Dust collectors can be employed to prevent dust emissions during hopper loading, especially for materials with high dust content.
Dry bulk packaging systems are used to fill powdered or granular materials into bags, drums, jars, sacks, etc. Bulk materials delivered in big bags must be transferred to packaging machines without interruption. The loading hopper of the packaging system should remain full during the filling and packaging process. Big bag discharge systems can monitor the product level in the loading hopper and maintain a constant level automatically. Depending on the packaging speed, mechanical conveying systems or pneumatic loading systems can be selected. Dust collectors can be used to prevent dust emissions during hopper loading, especially for materials with high dust content.
Mixer automation systems are used to mix dry bulk solids according to specific recipes. Raw materials delivered in FIBC bags can be transferred to mixing units through a combination of conveying equipment and bulk bag discharge systems. Depending on the type of application, pneumatic conveying or mechanical feeding systems can be used to fill mixers. Big bag discharge stations can be manufactured with built-in dosing systems. The amount of raw material to be loaded into the mixer is automatically controlled with the help of a weighing and dosing system. Dust collectors can be used to prevent dust emissions during the mixer filling process.
Bulk material stored in big bags can be automatically filled into small bags. Big bag discharge systems come with optional built-in bag filling units. For low filling capacities, these units are installed below the big bag discharge hopper, providing a practical and cost-effective solution. Both big bag discharging and bag filling operations can be handled by a single, compact system. For higher bag filling needs, bag filling machines are installed near the bulk bag discharge stations. Pneumatic conveying systems or mechanical conveyors can be used to transfer bulk material from the FIBC bag discharge station to the bag or sack filling system.
Mechanical conveyors can be used for silo loading from big bag discharge stations. Screw feeders, bucket elevators, rotary valves, or chain conveyors are connected to big bag discharge stations to fill silos. The selection of conveying equipment directly depends on the conveying distance, height, transferred material, and capacity. Bucket elevators are preferred for high silos, while screw feeders are preferred for shorter silos and short distances. The big bag discharge system can be installed on top of the silo for faster filling. In this case, rotary valves or butterfly valves are better choices as they provide simple flow control. Dust collection systems may be required depending on the dust content of the bulk solid. During silo loading, air content in the silo escapes to the atmosphere and carries some dust along with it. Vacuum fans and jet filters in dust collectors prevent dust emissions into the environment. The collected dust is sent back to the silo, thus preventing product loss.
Pneumatic conveying systems installed after bulk bag discharge units transfer bulk material through conveying pipelines to fill silos. This configuration is useful in applications where high transfer rates and long conveying distances are needed. In production lines where raw materials are stored in warehouses far from storage silos, bulk bag discharge stations can be installed close to the warehouses, and pneumatic conveying systems are used to fill silos from long distances. This design reduces the need for forklifts and cranes for bulk material transfer on the production site and increases overall efficiency.
Pneumatic conveying systems used for silo loading utilize blower pumps or compressors. Motor power, pipeline diameter, and equipment selection depend on the type of bulk material, transfer distance, silo height, and transfer capacity. Level sensors, jet filters, and other equipment are installed on storage silos to ensure the proper operation of the silo filling system.
Pneumatic conveying systems installed after bag dump units transfer bulk material through pipelines to fill silos. This configuration is ideal for applications requiring high transfer rates and long conveying distances. In production lines where raw materials are stored in warehouses far from storage silos, bag dump stations can be installed close to warehouses, allowing pneumatic conveying systems to transport materials over long distances. This design reduces the excessive use of forklifts and cranes for bulk material transfer within the production site, improving overall efficiency.
Pneumatic transfer systems used for silo loading utilize blower pumps or compressors. Motor power, pipeline diameter, and equipment selection depend on factors such as the type of bulk material, transfer distance, silo height, and transfer capacity. Level sensors, jet filters, and other equipment are installed on storage silos to ensure the proper operation of the silo filling system.
Mechanical conveyors can be used for silo loading from bag dump stations. In this configuration, screw feeders, bucket elevators, rotary valves, or chain conveyors are connected to bag dump stations to fill silos. The selection of conveying equipment depends on factors such as conveying distance, height, material properties, and capacity. Bucket elevators are preferred for high silos, while screw feeders are ideal for shorter silos and short distances. Bag dump systems can be installed on top of the silo for faster filling. In such cases, rotary valves or butterfly valves are better choices as they provide simple flow control.
Dust collection systems may be required depending on the dust content of the bulk solid. During silo loading, air inside the silo escapes to the atmosphere, carrying dust particles with it. Dust collectors equipped with a vacuum fan and jet filter capture airborne dust. The collected dust is returned to the silo, preventing product loss and ensuring a cleaner environment.
The inlet skirt is an optional feature designed to extend the lifespan of the flexible connector sleeve. Its upper portion is attached to the outlet port of the upstream equipment and extends down into the bin activator’s inlet port. The primary function of the inlet skirt is to serve as a protective shield, safeguarding the flexible connector seal from wear and damage.
A vibratory motor is externally mounted to the bin activator. When powered, the motor generates vibrations that facilitate a steady flow of dry bulk materials within the system. Depending on the application requirements, one or two vibratory motors can be installed externally.
To accommodate a bin activator, the cone of a silo must be shorter than usual, resulting in a wider outlet. A flange supplied with the bin activator is separately welded to the silo’s outlet, slightly above the opening, at the production site. Once installed, the vibrating bin discharger is securely bolted to the flange, ensuring a stable and reliable connection.
Special spring suspension links and an engineered polymer seal work together to create a flexible connection between a vibrating bin discharger and the equipment positioned above it.
The proper design and installation of the polyurethane seal prevent it from slipping off and ensure a secure seal, eliminating the risk of dry bulk material leakage. Additionally, the seal offers high stress resistance and long-term durability, withstanding stresses caused by motor vibrations, pressure conditions, and other operational factors.
Externally installed spring suspensions provide full resilience to the vibrations of the cone head. They ensure that the generated vibrations affect only the cone itself rather than the upstream equipment structure.
An internally tapered, conical-shaped baffle plate is positioned at the center of the bin activator’s diameter. The baffle is rigidly attached to the equipment body using structural steel components. It facilitates bulk material flow from upstream equipment by directly inducing vibrations into the material.
A secondary deflector plate reduces the weight of the bulk material in the lower portion of the bin activator by acting as a wedge beneath the material, directing it around the areas adjacent to the cone’s surface.
Polimak baffle plates are available in various configurations, including convex and cone plates, and in different angles (15°, 30°, 45°, or even 60°) depending on the flow characteristics of the handled bulk material and the specific application requirements.
