Functions of a Butterfly Valve
- Flow regulation: Flow can be easily controlled or regulated simply by turning the valve wheel.Using a flow controller...
- Flow Isolation
- Prevention of Backflow: Butterfly valves can be used for backflow prevention in some situations.
What are the functions of the butterfly valve?
Mar 21, 2022 · A butterfly valve is a type of quarter turn valve. A quarter turn valve can open or close whenever the handle is turned 90 degrees (a quarter of a turn). The main function of these valves is to control the flow of liquids through a section of pipe. Butterfly valves are mainly used in waste treatment systems.
What are the advantages and disadvantages of butterfly valve?
Jun 29, 2015 · In other words, a butterfly valve consists of a circular disc or plate built with a stem through the middle or attached offset. When opened, the disc pivots 90° in the valve bore, aligning with the flow and creating a nearly unrestricted flow path. Like ball valves, butterfly valves rotate 90° to enable quick shutoff.
What is the working mechanism of a butterfly valve?
Nov 15, 2021 · A butterfly valve regulates flow by starting, slowing, or stopping media. The disk opens and closes with a low-torque rotation of 90 degrees and works for any compatible application. Because they cost less and are lighter weight, the butterfly valve is often preferred over other types of valves.
What are butterfly valves used for?
A butterfly valve is a type of quarter turn valve. A quarter turn valve can open or close whenever the handle is turned 90 degrees (a quarter of a turn). The main function of these valves is to control the flow of liquids through a section of pipe. Butterfly valves are mainly used in waste treatment systems.
What are butterfly valves good for?
Butterfly valves are used where space is limited. Unlike gate valves, butterfly valves can be used for throttling or regulating flow as well as in the full open and fully closed position. The pressure loss through a butterfly valve is small in comparison with the gate valve.
What is butterfly valve and how it works?
Butterfly valves are among the family of quarter-turn valves and work very similar to ball valves. The “butterfly is a disk connected to a rod. It closes when the rod rotates the disc by a quarter turn to a position perpendicular to the flow direction (right image in Figure 1).
Where are butterfly valves used?
Butterfly valves are used for applications that require handling large volume capacities. It can be used for flow control and regulation and on/off service. Recent developments have permitted this type of valve to throttle more accurately and perform well in high-temperature and high-pressure applications.
Why butterfly valve is used in engine?
Butterfly valves are generally favored because they cost less than other valve designs, and are lighter weight so they need less support. The disc is positioned in the center of the pipe. A rod passes through the disc to an actuator on the outside of the valve.
Do butterfly valves have a flow direction?
The butterfly valves are bi-directional but do have a preferred flow direction. It's however strongly recommended to install the valves in the preferred flow direction, as it will extend the valve's life span and will also lower the operating torque.Oct 25, 2017
What are diaphragm valves used for?
Diaphragm valves are bi-directional, on-off throttle valves. They are used to control fluid flow by regulating the area with which media can enter and exit the valve, effectively changing its speed and velocity.
Are butterfly valves good for isolation?
Butterfly valves offer true isolation and control capabilities in a single product. Designed for accurate flow and pressure control, they are ideal in applications where positive isolation is required.
What are valves used for?
A valve is a device or natural object that regulates, directs or controls the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing various passageways.
Do butterfly valves need gaskets?
The seat in a resilient-seated Butterfly valve usually extends around to both faces of the valve. As a result, no gaskets are required as these seats serve the function of a gasket. The seat material which extends past the face is compressed during installation and flows toward the centre of the valve seat.4 days ago
Why do butterfly valves fail?
The primary failure modes for valves are the valve leaks to environment through flanges, seals on the valve body, valve stem packing not properly protected, over tightened packing nuts, the valve cracks and leaks over the seat.Jul 11, 2016
How many turns does it take to close a butterfly valve?
The handwheel or nut must be rotated through 35-290 turns (depending on model) to open or close the butterfly valve.
What is the difference between a ball valve and a butterfly valve?
Flow regulation: Both valve types can be used for on/off control and proportional control, but ball valves are typically used for proportional due to better flow regulation. Ports: A butterfly valve can only have two ports, while a ball valve can have more than two ports.
What is a butterfly valve?
In a more technical tone, a butterfly valve is a regulated rotary valve that consists of a rotating disk which directs the flow of fluid in a system. Basically, the disk is operable up to 90 degrees and that’s why it is called a quarter-turn valve. A butterfly valve controls the flow linearly and can be bi-directional.
How does a butterfly valve control flow?
Basically, when a flow monitor senses that a set parameter (differential pressure) has been reached , it will signal the valve actuator to close or open the valve.
Why use butterfly valves in food?
In food industries where there are aggressive washdown processes, butterfly valves can be used for backflow prevention. This is necessary, from standard regulations, as it is aimed in food processing to deliver procedures in sanitary conditions.
What type of valve is used for throttling?
For throttling services, you can use a high performance butterfly valve, which is a higher industry standard for larger applications. Generally, this type of valve is manufactured to process large capacities and oftentimes, viscous and seawater medium. We will get more into high performance butterfly valves later.
Can you choose the mode of operation of a butterfly valve?
Manufacturers and suppliers usually have a range of choices for this. They would have manually operated, semi-automatic or automatically-operated valves. This would depend on the location of your valve, application, cost and on how often you need to turn on and off the valve.
What is AWWA valve?
For example, lightweight and AWWA butterfly valves are meant for water lines and potable water control applications. Other light duty valves can be used for aquariums and sprinkler systems. Some valves are also meant for fuel flow control.
Is a butterfly valve the same as a ball valve?
The butterfly valve with the same specification as the ball valve is usually cheaper in price and easier to install. Easier maintenance may go in recognition to ball valves as butterfly valves have a disc that can block some impurities that got stuck. Furthermore, ball valves are used in most high-pressure applications because they are more suitable for high differential pressures as compared to butterfly valves.
How do butterfly valves work?
The construction of a butterfly valve is relatively simple, with the rotation of the valve disc controlling the fluid flow. In the closed position, the disc blocks the valve bore while in the open position, the disc is oriented perpendicular to the flow direction to allow flow. Butterfly valves generally provide bi-directional flow and shutoff capability. However, they are not full-bore, which renders them unsuitable for pigging or swabbing. The body material is ductile iron with an epoxy powder coat on both internal and external surfaces. The valves are typically operated by handwheels, gears, or actuators, or a combination thereof, according to the specific application requirement and technical specifications. We will be discussing the actuation methods later in the article.
What is butterfly valve?
Butterfly 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.
What are the advantages of butterfly valves?
Depending on the application, butterfly valves can offer significant advantages over other types of valves, especially for dimensions over DN 200 (200 mm) in size: 1 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. 2 Low Maintenance Requirements: An inherently simple, economic design that consists of few moving parts, and hence fewer wear points, significantly reduces their maintenance requirements. 3 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. 4 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, typically above DN 300. 5 Versatility: Butterfly valves have a wide variety of use cases including the ability to be installed underground.
How are valves operated?
The valves are typically operated by handwheels, gears, or actuators, or a combination thereof, according to the specific application requirement and technical specifications. We will be discussing the actuation methods later in the article. 04.
What are the components of a butterfly valve?
Below are the major components of a butterfly valve. Besides, there are smaller more common components such as the bushings, bearings, and fasteners that are part of most other valve constructions as well. Details on some of the components on the actuation end, such as the handle, lever, gearbox, and handwheel will be covered in ...
What is the valve body?
The valve body fits between the pipe flanges - the most common end connection types being flanged, double lug, and wafer types. Attached to the valve body is the disc that functions as a gate that stops or throttles fluid flow; it can be considered equivalent to a gate in a gate valve, or a ball in a ball valve.
What is pneumatic valve?
Hydraulic: Typically used for applications requiring large torques for opening and clo sing the valve, such as high pressure and high viscosity applications.
How does a butterfly valve work?
Understanding the way a basic butterfly valve works is pretty simple. It can help you to learn more about the components of valves. Butterfly valves are made of a number of components. The most important one is the metal disc. This metal disc is the one commonly referred to as the butterfly. The butterfly is mounted on a rod and when ...
What is butterfly valve?
A butterfly valve is a type of quarter turn valve. A quarter turn valve can open or close whenever the handle is turned 90 degrees (a quarter of a turn). The main function of these valves is to control the flow of liquids through a section of pipe.
What are the components of a butterfly valve?
There are many other components that form the butterfly valve. They include the resilient seat, body, packing, a stem and an actuator. The resilient seat is mounted on the body of the butterfly valve in order to provide the proper seal.
What happens when a valve is fully open?
When the valve is fully open, the metal disc or butterfly moves a quarter turn. The passageway is unrestricted allowing fluids or air to pass. In essence, the movement of the disc will depend on whether the valve is open or closed either partially or completely. If the valve is opened partially, it means that the disc will not be rotated ...
What is butterfly valve?
The term “butterfly” in a butterfly valve is actually a disk that is connected to a rod. When this rod rotates the disk by 90° the butterfly valve opens or closes.
Why are butterfly valves so popular?
Butterfly valves are popular in industry because of their lightweight, fast operation, and low costs. These valves use handles, gears, or automatic actuators for operation as per the requirement.
What are the components of a butterfly valve?
There are four main components in a butterfly valve: body, disk, stem and seat. Valve body: the body of the Butterfly valves fits two pipe flanges, the most common body design is lug and wafer type (Fig. 2). Butterfly valve disk: The disk (disc) is the element that stops the flow. For improving flow, sealing, and operating torque, ...
What are the disadvantages of butterfly valves?
Throttling service is limited to low differential pressure. Disc movement is affected by flow turbulence. The valve disc is always under pressure and can interrupt the flow even in an open position.
What is a butterfly valve?
Damper valves are used for air flow control and diversion applications. A butterfly valve is a damper that has only one wafer to control airflow. A louvered damper has multiple wafers that open/close to control airflow. All butterfly valves are damper valves, but not all damper valves are butterfly valves.
What are the advantages of butterfly valves?
Butterfly valves also offer weight, space and cost savings that are difficult to achieve ...
