What are the different types of VG flanges?

　　VG flange is one of the standard flanges used for pipeline and equipment connections, widely used in various industrial fields, especially in industries such as petroleum, chemical, power, aviation, etc. According to different standards and application requirements, there are several different types and specifications of VG flanges, mainly including the following types:

　　1.Butt Weld Flange: This type of flange is also commonly used in areas that require welding, and the connection becomes tighter after welding, making it suitable for applications that can withstand high temperatures and pressures.

　　Loose flange: Loose flanges can be loosely fitted onto pipelines or equipment, suitable for situations that require disassembly and maintenance.

　　Threaded Flange: Threaded flanges are connected by threads and are suitable for situations that do not require welding. They are easier to install but are suitable for lower pressures and temperatures.

　　Clamp flange: fixed by clamping, commonly used in places that require frequent disassembly or convenient disassembly.

　　2. Classify by pressure level

　　VG flanges can be classified according to pressure levels, and common pressure levels include:

　　Low pressure flange: suitable for lower pressure applications, generally PN6, PN10, etc.

　　Medium pressure flange: suitable for applications with medium pressure, common pressure ratings include PN16, PN25, etc.

　　High pressure flange: suitable for high-pressure environments, generally PN40, PN63, PN100, etc.

　　3. Classify by shape

　　Flat flange: The flange surface is flat and suitable for low-pressure piping systems.

　　Raised Face Flange (RF): The face of the flange has a certain protrusion, which can provide better sealing and is suitable for high-pressure environments.

　　Flat Faced Flange (FF): The flange surface is flat without protrusions and is commonly used to connect with other flat flanges.

　　Concave flange: This type of flange has a concave surface, which can improve the sealing effect and is suitable for situations that require higher sealing performance.

　　4. Classify by flange size

　　The size of VG flange can be customized according to the diameter and pressure rating of the pipeline. Common standard sizes include:

　　Small diameter flange: suitable for small diameter pipelines, with common diameters ranging from DN10 to DN50.

　　Medium diameter flange: suitable for medium diameter pipelines, such as DN65 to DN150.

　　Large diameter flange: suitable for large diameter pipelines, with common diameters ranging from DN200 to DN1200 or even larger.

　　5. Classify according to connection standards

　　Different regions and industries may adopt different flange standards, and VG flanges also have corresponding standards. Common standards include:

　　VG standard flange: VG is a flange standard in Germany used to fix the size, pressure rating, sealing surface shape, etc. of flanges, mainly used in Germany and some regions of Europe.

　　DIN standard flange: a German standard widely used in the industrial field.

　　ANSI/ASME standard flange: mainly used in North America, using imperial units, suitable for flanges of different pressure levels.

　　JIS standard flange: a flange standard applicable to Japan and commonly used in East Asia.

　　6. Classify by material

　　VG flanges can also be classified according to the materials used, with common materials including:

　　Carbon steel flange: commonly used in conventional pressure and temperature environments, with a relatively cheap price.

　　Stainless steel flange: suitable for corrosion-resistant environments, usually used in industries such as chemical and food.

　　Alloy steel flange: suitable for applications in high temperature, high pressure, and highly corrosive environments.

　　Cast steel flange: manufactured using casting technology, suitable for medium and low pressure environments..

　　There are various types of VG flanges, and the appropriate type can be selected based on factors such as usage environment, pressure rating, connection method, size, and material. Choosing VG flanges correctly can help improve the sealing, stability, and safety of pipeline systems. Different types of VG flanges play important roles in different industrial fields and working conditions.