What is Butterfly Control Valve
Butterfly control valves are a family of quarter-turn rotational motion valves that are used in pipelines to shut-off flow. It is often said that butterfly valves can be used to regulate the flow. However, we do not recommend doing this, as it can damage the valve disk and have a negative effect on the sealing properties. They are used in a wide variety of process media and industries especially in water supply, collection, and distribution, as well as pumping stations, and have a broad range of use cases especially in flow isolation. A couple of their key advantages over other valve families are their simple construction and compactness, resulting in the end products being of lighter weights and lower cost and with smaller installation footprints and faster actuation speeds.
Lightweight and compact
Butterfly valves are great for several applications because they are very lightweight and provide reasonable flow control in a compact design. You will generally want to use a metal-seated valve for more extreme fluid processing, while a soft-seated butterfly valve is best for applications with low pressures and temperatures.
Simple and cost effective
Butterfly valves are very simple in design and have minimal maintenance requirements. They are easy to install and operate. Plus, they are typically much less expensive than a ball valve of the same size. They do not require much torque to operate effectively and can be automated for energy-efficient operation.
Quick and efficient
The 90-degree turning radius allows for quick sealing upon actuation, which provides more accurate flow control with minimal effort to turn the valve on and off. Different butterfly valves are to consider, including zero-offset, double-offset, and triple-offset. The pressure will usually determine which type you need. The higher the offset, the more pressure the valve can handle.
Pressure control
In addition to precision flow control, butterfly valves are excellent for pressure control. They experience minimal pressure drop during operation before the fluids recover energy quickly after leaving the valve. This keeps the pump system running efficiently with consistent fluid pressures.
Why Choose Us
Our Product
Pneumatic/ Electric Single Seat Control Valve, Pneumatic/ Electric Sleeve Control Valve, Pneumatic/Electric V-shaped Control Valve, Pneumatic/ Electric Shutoff Butterfly Valve, Pneumatic/ Electric Control Butterfly Valve, Pneumatic/ Electric Shutoff Ball Valve, Pneumatic/ Electric Control Ball Valve, Self-operated Regulating valve, desuperheating and pressure reducing device, pneumatic/ electric eccentric rotary valve.
Product Application
Valves are widely used in petroleum, petrochemical, electric power, chemical industry, coal chemical industry, coal-to-liquids, metallurgy, mining, nuclear power energy, papermaking, pharmaceutical manufacturing and many other industries ISO9001 quality management system certification, ISO14001 environmental management system certification, ISO45001 occupational health and safety management system certification, special equipment production license, SIL valve certification, a variety of innovative patents.
Production Market
The company focuses on the Chinese market, has in-depth and close cooperation with many large groups in China, is responsible for many large-scale projects every year, and achieves increasing performance results. At the same time, the company has strategically deployed markets in various countries, and has cooperated with multinational companies in Russia, India, Germany and other countries on projects, and its overseas market performance has increased by 100% in 2021.
Our Service
Pre-sales professional engineers are responsible for calculation and selection and answering customers' doubts, giving professional answers and professional opinions on valve working conditions, and 1-to-1 professional personnel to introduce and guide products, allowing customers to choose There will be no professional doubts.
Components of a Butterfly Control Valve
Valve body: Made from a tough and rigid material, the valve body houses and protects the disc and other internal components of the butterfly valve. It links the valve to the piping system and to the external operating mechanism that controls the disc.
Disc. The disc permits, regulates, and stops the flow of the fluid in the pipeline. Flow is controlled by the rotary motion of the disc. The discharge flow rate depends on the degree of disc opening.
When the disc is perpendicular to the flow’s cross-sectional area, the fluid is fully obstructed from flowing out of the valve. Otherwise, the fluid is permitted to flow through the space between the seat and the disc. It takes a 90° rotation from the closed position of the disc to allow full opening or closing of the valve. Flow is throttled when the disc is rotated less than 90°.
Stem: The stem is a shaft that connects the disc to the external operating mechanism. It is sealed by O-rings and bushings to prevent fluid leakage. The stem can be made from a one-piece shaft or two-piece (split-stem) shaft. The placement of the stem axis and its connection to the disc depends on the type of butterfly valve.
Seat or sealing ring: The valve seat for basic concentric butterfly valves is a ring that provides sealing between the disc edge and the valve body when it is in a closed position. Its sealing action is necessary to avoid leakage of any fluid to the discharge of the butterfly valve. Since the disc slides on the surface of the seat during valve opening, it must be made from a material with a low coefficient of friction.
The butterfly valve seat can be made a soft seat or a metal seat. The material of the seat limits the temperature and pressure rating of the butterfly valve. Soft seats, which are made from plastic and elastomeric materials, are limited to lower temperature applications because they deform at elevated temperatures. Metal sealing rings are capable of performing at higher temperatures and have a longer seal ring life but are difficult to completely seal.
Operating mechanism: The external operating mechanism of a butterfly valve controls the fluid flow across the valve. It may be operated by manual rotation of the stem or by automatic actuation.
Manual operation of butterfly valves involves the application of torque to the lever or handwheel attached to the stem. Levers can set the valve into a closed, fully-opened, or partially-opened position. Larger butterfly valves are equipped with handwheels and gearboxes to increase torque and to aid in the opening and closing of the valve.
Triple offset: Tripled offset has three eccentrics each of which is located differently in the valve. The eccentrics are placed in an offset position to form an offset conical profile creating a right angle cone.
Bushing or bearing: The quality and type of bushing determines the longevity of a butterfly valve. The best bushings are resistant to corrosion and wear and used for precision control, current limiting, and switching of chemicals, petrochemicals, chlorine, paper production, and electroplating.
Zero offset butterfly valves (resilient seat butterfly valves)
In zero offset butterfly valves, also known as concentric butterfly valves, the stem passes through the centerline of the disc that is centered in the seat; all of this is centered inside the valve body. The valve body, seat, and disc lie concentrically when it is in a closed position. The disc rotates on the central axis; this allows a 360° rotation. In a fully-opened position, the flow is divided into two halves on each side of the disc, which is now parallel to the flow.
Double offset butterfly valve (high-performance butterfly valves)
In double offset butterfly valves, the stem axis is offset behind the centerline of the seat and the body (first offset), then the stem axis is further offset from the vertical centerline of the valve (second offset). When the disc is opened, the seat is lifted from the seal; this reduces the friction during the first and last 10 degrees of the valve opening and closing, respectively. This results in a smoother valve operation, better sealing capability, and longer service life than the zero offset butterfly valve.
Triple offset butterfly valve
In triple offset butterfly valves, an angular offset in the body sealing cone axis is made in addition to the first two offsets (third offset). This is accomplished by using the right-angled conical profile of the seat coupled with a matching profile at the disc edge. This offset eliminates the contact of the seat and the disc during valve opening and closing, hence, friction is also eliminated. Contact only occurs during the full closure of the butterfly valve; this also acts as a mechanical stop to prevent the disc from rotating further.
Wafer butterfly valve
In wafer butterfly valves are placed between two pipe flanges, which are linked by long bolts across the valve body. The valve body may or may not have flange holes outside the valve body. O-rings and gaskets that are mounted in a flat valve face are placed on both sides between the valve body and the pipe flange to achieve a strong seal.
Lug butterfly valve
Lug butterfly valves are placed between two pipe flanges by the bolts that pass through the threaded inserts (or lugs) protruding outside the valve body. The valve is supported by two separate sets of bolts on each side of the valve and no nuts are used in either lug. This enables the valve to become an isolation valve or to be installed in an end-of-line service. This design enables dismantling on one side of the valve without it affecting the other; this lessens the downtime during maintenance.
Double-flanged butterfly valve
Double-flanged butterfly valves have a pair of flanges built on each side of the valve body; these match the dimensions of the pipe flanges. Two sets of bolts and nuts are used to support the valve on each side; this produces a strong attachment. Double-flanged butterfly valves are more popular in butterfly valves with larger sizing.
8 Things You Must Know When Choosing a Butterfly Control Valve
Butterfly valve application
The first thing to consider is the application for which the butterfly valve will be used. Different types of butterfly valves are designed for different applications, such as high-pressure or high-temperature environments, corrosive or abrasive fluids, and so on.
Butterfly valve size
Butterfly valves come in a variety of sizes, so it's important to choose the right size for your piping system. Consider the pipe size and flow rate when selecting the valve size.
Butterfly valve material
The material of the valve body, disc, and stem must be compatible with the fluid being handled. Some common materials used for butterfly valves include cast iron, stainless steel, pvc, and bronze.
Butterfly valve disc type
The disc of the butterfly valve can be either concentric or eccentric. Concentric discs are used for low-pressure applications, while eccentric discs are used for high-performance applications.
Butterfly valve seat type
The seat of the butterfly valve can be either resilient or metal. Resilient seats are made of materials such as rubber or ptfe and are suitable for handling corrosive fluids. Metal seats are more durable and are suitable for high-temperature applications.
Butterfly valve end connections
Butterfly valves come with a variety of end connections, such as flanged, threaded, or wafer-style. Choose the end connection that matches the piping system being used.
Butterfly valve actuation
Finally, consider how the butterfly valve will be actuated. Valves can be manually operated, or they can be automated with electric or pneumatic actuators. Choose the actuation method that best suits the application and the level of control required.
Butterfly valve price
Butterfly valves of the same size will appear in many prices, and one of the most important factors in reference to the price is whether the material content is up to standard and whether the weight is sufficient. The weight of the butterfly valve varies from body to body, and of course you can choose the body you like. The valve with too low a price is likely to have a material that is not up to standard.
Butterfly Control Valve Installation Tips as Well as a Checklist to Take Note Of
In order to check parts of the butterfly valve, you can be able to disassemble it in order to further inspect its parts.
Before anything, see to it that the flange and pipeline are clean from foreign materials. These can damage the seat or disc and can also cause disc to movement restrictions.
Since resilient seated valves extend to both faces, gaskets are not needed.
In order to easily insert the valve body, spread the flanges and align the pipe-work. With this the valve body is inserted even with no contact to pipe flanges.
Partially open the valve disc to prevent the valve from jamming.
Insert the valve between the flanges, taking care not to damage the seat faces.
When you lift the valve, hold it by the locating holes. Also, you can tie up a nylon sling around the body or the neck.Make sure you do not lift the valve at the actuator or its operator.
Once the valve is placed and aligned in between the flanges, insert all the bolts before hand-tightening them.
Slowly open the disc. This will test if it has the right clearance form the inside of the pipes.
Afterwhich, a gradual closure of the valve should also be done to verify enough clearance from the disc to the pipe flanges.
Fully open the valve, and start to tighten all of the bolts.
To test proper clearances after fastening the valve in the pipeline, repeatedly fully open and close the valve. This ensures the valve functions well during operation.
1. The butterfly control valve needs to be fully open and fully closed periodically during the working process to maintain the flexible lubricity of the valve parts and avoid rusting.
2. When closing the butterfly control valve, if it is not tightly closed, you can first fully open the butterfly valve again, use the pressure of the fluid in the pipeline to flush out the impurities on the inner wall of the valve, and then close the valve again.
3. Try to filter the impurities in the pipeline as much as possible to avoid squeezing the sealing surface when the butterfly valve is closed, causing the valve to fail to close completely, causing leakage, and causing safety hazards.
4. The opening state of the butterfly plate of the butterfly control valve should be greater than 15°, because if the butterfly valve is in a state with a large throttle range, the back of the butterfly plate is prone to cavitation and the valve is at risk of damage.
5. When the butterfly control valve is in the middle opening, the operating mechanism needs to be self-locking.
6. Prevent the butterfly control valve from mechanical damage, and don’t let the sediments, chemicals, damp gas and other substances in the air corrode the valve and affect the quality of the valve.
7. The threads, bearings, gears and other parts of the working interface of the butterfly control valve should be regularly lubricated.
FAQ
We're professional butterfly control valve manufacturers in China, specialized in providing high quality customized products. We warmly welcome you to buy durable butterfly control valve at competitive price from our factory. For pricelist and quotation, contact us now.
agriculture straight stroke control valve, valve for straight stroke control, industrial control valve