Introduction to the Lug Style Butterfly Valve.

As a common type of valve, the lug style butterfly valve has several remarkable features, which make it widely applied in industrial pipeline systems.

What is a lug style butterfly valve?

I. Structural characteristics of the lug style butterfly valve.

Flange Connection: The lug style butterfly valve is connected to the pipeline through a flange. This method makes the connection between the valve and the pipeline more stable, and it is suitable for medium and large-sized pipeline systems. At the same time, the flange connection also makes it convenient for the installation and disassembly of the valve, improving the convenience of maintenance.
Lug Design: There are usually two forms on the lugs. One is a through hole (commonly known as Type A), and the other is a through hole with internal threads (known as LT type). These two designs are respectively suitable for different installation scenarios, providing more installation options.
Double Eccentric Structure (Some Models): Some lug type butterfly valves adopt a double eccentric structure design. This design enables the valve to have relatively small friction and torque when opening and closing, thus improving the valve’s response speed and service life.

II. Performance characteristics of the lug style butterfly valve.

Good Sealing Performance: The lug style butterfly valve usually uses a sealing gasket to ensure the sealing performance. Some models also have a triple sealing structure (two layers of seals and one layer of metal seal), which can maintain good sealing performance under high temperature, high pressure and corrosive media.
Quick Opening and Closing: The lug type butterfly valve can be opened and closed quickly, enabling rapid control of the passage and interruption of the medium, and improving the operation efficiency of the pipeline system.
Strong Corrosion Resistance: The valve body and valve disc are made of materials such as stainless steel (SS304, SS316, SS304L, SS316L, etc.), making the lug type butterfly valve have good corrosion resistance and be applicable to a variety of medium environments.
Easy to Operate: The lug type butterfly valve is easy to operate and control. Some models are also equipped with reliable operating handles and electric devices, ensuring precise control and convenient remote operation.

double eccentric lug style butterfly valve

III. Application Fields of the lug style butterfly valve.

Due to its excellent performance characteristics, the lug type butterfly valve is widely used in fields such as petroleum, chemical industry, smelting, papermaking, and environmental protection. In these fields, the lug type butterfly valve plays important roles such as connecting, cutting off, regulating the pressure and flow rate of the medium.

IV. Other Characteristics of of the lug style butterfly valve.

Novel and Reasonable Design: The lug type butterfly valve has a novel and reasonable design, a compact structure, and a light weight, making it easy to carry and install.
Replaceable Sealing Parts: The sealing parts of the lug type butterfly valve can be replaced, which ensures the sealing performance of the valve during long-term use.
Flow Characteristics Tend to be Linear: The flow characteristics of the lug type butterfly valve tend to be linear, which gives it better accuracy and stability when regulating the flow rate of the medium.

In conclusion, the lug butterfly valve plays an important role in industrial pipeline systems with its unique structural design and excellent performance characteristics.

lug vs wafer butterfly valve.

What is a wafer butterfly valve?

The disc of a wafer butterfly valve is installed in the diameter direction of the pipeline. The disc rotates around the axis, with a rotation angle between 0° and 90°. When it rotates to 90°, the valve is in the fully open state. Wafer butterfly valves are generally installed horizontally. They have a simple structure, a small volume, and a light weight, consisting of only a few components. And it can be quickly opened and closed by rotating 90°, with simple operation. At the same time, it has good fluid control characteristics. When the butterfly valve is in the fully open position, the thickness of the disc is the only resistance when the medium flows through the valve body. Therefore, the pressure drop generated through this valve is very small, so it has better flow control characteristics.

Differences between a lug butterfly valve and a wafer butterfly valve.

The main difference between the lug type butterfly valve and the wafer butterfly valve lies in the connection method. The wafer butterfly valve uses a clamping method to connect the pipeline, while the lug type butterfly valve is connected to the pipeline through a flange. Due to the different connection methods, their installation methods are also different. Wafer butterfly valves are often installed using methods such as direct welding, ferrule welding, and flange connection. While lug type butterfly valves are often installed using flange connection and ferrule connection.

In addition, their sealing structures are also different. The clamping structure of the wafer butterfly valve makes its sealing performance relatively better, while the lug type butterfly valve uses a sealing gasket to ensure the sealing performance.

The overview of the lug style butterfly valve in practical applications.

Advantages of lug type butterfly valves:

Stable flange connection for medium to large pipelines, enabling easy installation, maintenance, and disassembly.
Versatile lug designs (e.g., through-holes with/without threads) offer flexible mounting options.
Good sealing performance, often with triple-seal structures, suitable for high-temperature, high-pressure, and corrosive media.
Quick operation (90° rotation for full open/close) and low friction/torque (in dual-eccentric models), improving efficiency and lifespan.
Corrosion resistance due to materials like stainless steel, suitable for diverse media environments.
Compact, lightweight design with replaceable seals, ensuring long-term reliability and easy repair.
Linear flow characteristics for precise flow regulation.

Disadvantages:

Require more space and bolts for flange installation compared to wafer types, potentially increasing installation time and cost in some cases.
Generally more complex and heavier than wafer-style butterfly valves, making them less ideal for very small pipelines or lightweight systems.