Definition of flange
Flange, also known as flange flange or flange, is a pipe fitting used to connect two pipes or equipment. Flanges are generally cylindrical structures, and their inner diameter can be processed and adjusted as needed. The equipment usually has threads that match the pipe mouths of the pipes or equipment to which it is connected, and they are fastened by bolts, thereby achieving a compact sealed connection. This structural form is simple, reliable and low-cost. The flange part is designed with holes, which facilitates the insertion and tightening of bolts, and gaskets are also provided between the flanges to improve their sealing. As the main tool for connecting pipes, Raised Face Weld Neck can ensure that there will be no leakage in pipelines or equipment, thereby bringing certain economic benefits to production. Simply put, flanges are a vital connection and sealing component in industrial applications.
Main types of flanges
There are many different types of flanges, and they can be classified from various different angles. Classifying them according to material properties and processing technology can not only meet the actual needs of production, but also ensure the quality of product manufacturing. Here are several commonly used classification methods:
1. Classification by connection method:
1. Threaded flange: connected to pipes or equipment by threads, with the characteristics of easy installation and convenient disassembly.
2. Welded flange: connected to pipes or equipment by welding, with high connection strength, suitable for harsh environments such as high pressure and high temperature.
3. Clamp flange: connected by clamping, suitable for some special occasions, such as occasions that require quick connection or disassembly.
2. Classification by industry standards:
1. Chemical industry standard flange (HG): including integral flange, threaded flange, plate flat welding flange and other types, suitable for the chemical industry.
2. Petrochemical industry standard flange (SH): including threaded flange, butt welding flange, flat welding flange, etc., suitable for petrochemical industry.
3. Mechanical industry standard flange (JB): including integral flange, butt welding flange, plate flat welding flange, etc., suitable for mechanical industry.
4. National standard flange (GB): covers a variety of flange types, with unified specifications and standards, facilitating intercommunication and interchange between different industries.
In addition, there is a special type of flange-flange cover (blind flange), which has no hole in the middle and is used to seal the pipe plug to play a sealing role.
Main materials of flanges
The material selection of flanges is crucial to their performance and service life. The following are several common flange materials and their characteristics and applications:
1. Carbon steel Alloy Steel Flanges: has good strength and toughness, suitable for general industrial fields, such as petroleum, chemical industry, machinery, etc.
2. Stainless steel flange: has excellent corrosion resistance and high temperature performance, suitable for occasions with high material requirements, such as food, medicine, etc.
3. Alloy steel flange: has higher strength and high temperature resistance, suitable for harsh environments such as high pressure and high temperature, such as petrochemical, power and other industries
Application scope of flanges
As a key component for connecting pipelines and equipment, flanges are widely used in many industrial fields. The following are the main application scopes of flanges:
1. Petroleum and chemical fields: Flanges are widely used in the petroleum and chemical industries to connect various pipelines and equipment to ensure the sealing and stability of the transmission medium.
2. Food and pharmaceutical fields: Due to the excellent corrosion resistance of stainless steel flanges, they are widely used in food, pharmaceutical and other industries to ensure the hygiene and safety of products.
3. Textile and machinery fields: Flanges also play an important role in textile, machinery and other industries, connecting various equipment and pipelines to ensure the smooth progress of production.
4. Construction, light and heavy industries, plumbing, electricity and other industries: Flanges are also widely used in these industries, providing reliable solutions for the connection of various pipelines and equipment.
Standard system of flanges
In order to ensure the interchangeability and compatibility of Alloy Steel Flanges, countries have formulated corresponding flange standards. The current flange standards in my country are divided into two systems: PN series (European system) and Class series (American system).
1.PN series (European system): The nominal pressure level of the PN series is expressed by PN, including nine levels such as PN2.5, PN6, PN10, PN16, PN25, PN40, PN63, PN100, and PN160. These levels indicate the load-bearing capacity of the flange under different pressures.
3.lass series (American system): The nominal pressure level of the Class series is expressed by Class, including six levels such as Class150, Class300, Class600, Class900, Class1500, and Class2500. These levels also indicate the load-bearing capacity of the flange under different pressures, but they are different from the PN series.
4.The formulation and implementation of flange standards are crucial to ensuring the quality and function of flanges. The national standard "Steel Pressure Vessels" is currently the only industry standard in my country that is specifically formulated for flange products used in the oil and gas industry. It is also the earliest set of mandatory standards for flanges used in the petrochemical industry issued in China. The regulation not only standardizes key parameters of flanges such as size, specifications and materials, but also clarifies the inspection and testing methods of flanges to ensure their reliability and safety.