What Is The Difference Between A Butterfly Valve And A Plug Valve?

Butterfly valves and plug valves are two completely different types of valves. They are obviously different in many dimensions such as structure, operation mode, actual use results and operating environment. Next, we will conduct an in-depth comparative study of the depth of these two types of valves:
1. In-depth exploration of the core ideas of structure and operation
Valves with butterfly shape
From the structural point of view, the butterfly valve is composed of a valve body, a valve stem, a butterfly plate and a sealing ring. The valve body is circular in structure and is equipped with a butterfly plate, which is a circular opening and closing component that can rotate around the central axis of the valve body.
The operation method of the butterfly valve is mainly to control the flow of the medium by rotating the butterfly plate about 90°. When the butterfly plate and the valve body channel are parallel, the medium can flow unimpeded; when the channel between the butterfly plate and the valve body is arranged vertically, the medium will be cut off.
Rotary valve
From the structural point of view, the plug valve is mainly composed of three parts: the valve body, the plug and the valve stem. The opening and closing components of the valve are designed with a plug (which can be conical or cylindrical), and its core function is to control the opening and closing of the valve by rotating the valve stem.
Operation Guide: The plug valve uses a rotating plug to adjust the flow state of the medium. The fluid can only flow smoothly when the passage opening of the valve body is aligned with the through hole on the plug; when the rotation of the plug causes the through hole and the passage opening of the valve body to be misaligned, the fluid will be effectively blocked.
2. About its performance and functional performance after use
It has a closed function
The sealing effect of the butterfly valve is determined by the sealing ring material used and the accuracy of the butterfly plate manufacturing. In many occasions, the butterfly valve usually performs well in terms of sealing, but compared with the plug valve, its performance may be slightly inferior.
A significant feature of the plug valve is that it has relatively few sealing surfaces, usually only involving the sealing work of the plug and the valve body, which makes its sealing effect very good, especially in application scenarios that require high sealing standards.
Obstructions caused by the flow
Butterfly valve: When the butterfly valve is fully extended, the resistance to the flow is reduced accordingly; however, when the butterfly plate is partially opened, the resistance to the flow increases, which may more easily trigger phenomena such as vortex and vibration.
Plug valves are characterized by relatively low flow resistance, because the sealing surface between the plug and the valve body can be linear or planar contact, which can reduce the resistance to the flow of the fluid.
Opening and closing speed
Butterfly valve: Since the rotation angle of the butterfly plate is only about 90°, the butterfly valve can be opened and closed quickly.
Plug valve: Although its opening and closing speed is relatively fast, it may be slightly slower than that of the butterfly valve, because the plug needs to be fully rotated to align or misalign with the valve body channel.
Management of the amount of flow
Butterfly valve: By adjusting the deflection angle of the butterfly plate, the butterfly valve can change the flow of the medium, but such adjustment may be subject to some restrictions.
The main design goal of the plug valve is to open or close the flow, or adjust the flow direction of the fluid, rather than to make frequent flow adjustments. However, in some specially designed plug valves, precise control of fluid velocity can also be achieved by adjusting the size of the channel on the plug.
3. Appropriate application scenarios
Valves with butterfly shape
Butterfly valves have shown wide applicability in many application scenarios such as water treatment, thermal energy systems and air systems, especially in large-diameter pipeline systems that require frequent operation, and their performance is particularly outstanding.
Butterfly valves are particularly suitable for applications that require rapid disconnection and flow adjustment, such as fire protection equipment and ventilation and air conditioning systems.
Rotary valves
Plug valves are widely used in many industries, including but not limited to petroleum, chemicals, natural gas, water supply and drainage, pharmaceutical manufacturing and food manufacturing.
Plug valves are particularly suitable for applications that require frequent operation and rapid switching, such as oil and gas transmission pipelines.
Plug valves are not only the best choice for handling fluids containing particles, but also perform very well in environments where precise flow control is required, especially in terms of sealing and operating performance.
4. Issues about price and maintenance
Details on price
While keeping the material and caliber unchanged, the price of butterfly valves and plug valves may be affected by various factors such as brand positioning, production process and market demand, resulting in different changes. In many occasions, the production cost of butterfly valves is often more economical, which is mainly due to the simplicity of its design structure and the convenience of the production process.
Perform routine maintenance and maintenance work
The design of butterfly valves is simple and convenient for partial disassembly and replacement, which makes its subsequent maintenance tasks easier.
Although the design of plug valves is relatively simple, due to the wear and tear of its sealing surface and the large switching force, more maintenance and parts replacement may be required.
When we conduct a comprehensive evaluation from many aspects, butterfly valves and plug valves have obvious differences in many fields such as their structural design, operation mode, actual use effect and applicable environment. In the process of selecting valves, we should decide the best model of valves according to specific operating specifications and working environment.