What is a Flange？

Flanges, also known as flanged discs or raised discs, are disc-shaped parts very common in mechanical and engineering installations. Flanges are usually used in pairs, mainly for connecting pipes to valves, pipes to pipes, and pipes to equipment, serving a sealing function. Since flanges are widely used for connections between these devices and pipelines, any connecting part that uses bolts between two planes and has a sealing function is generally called a "flange."

Structure and Features of Flanges

Flanges are typically circular disc-shaped structures with multiple holes for fixing. At the pipeline connection, a gasket is usually placed between the two flange discs, which are then tightened with bolts. Depending on the pressure requirements, the thickness of the flange and the specifications of the bolts will vary. The main materials for flanges include carbon steel, stainless steel, and alloy steel.

Applications of Flanges
Due to their important connecting and sealing functions, and their good comprehensive performance, flanges are widely used in various industries such as chemical, petrochemical, fire protection, and drainage. As a connecting piece, flanges are not only widely used domestically but also internationally. To ensure the uniformity and compatibility of flanges, different countries and regions have established their own standard systems. For example, the European pipeline flange system (represented by German DIN) and the American flange system (represented by ANSI) are the main flange standard systems currently. In addition, the Japanese JIS pipeline flange system and the Chinese GB steel pipeline flange system are also widely adopted.

Classification of Flanges

Integral flange (IF): Generally used in pipelines with higher pressure, usually made by one-time integral casting, and the material is mostly carbon steel and stainless steel.
Welding neck flange: When connecting to a container or pipeline, it adopts a welding method, which is easy to assemble and has a low price, mainly used in pipelines with less pressure and vibration.
Socket weld flange: Also known as a high-neck flange, it has a prominent high neck and is suitable for pipelines with high temperature, high pressure, and low temperature, which can increase the strength of the flange.
Loose flange: Also known as a slip-on flange, it is mostly used on non-ferrous metal and stainless steel pipelines, suitable for large-caliber and frequently disassembled connections, but the pressure resistance is not high.
Threaded flange: The flange disc has threads and is connected with an externally threaded pipeline, no welding is required, suitable for environments with large temperature changes.

Production Technology of Flanges

Forged flange: Through multiple hammering by a forging machine, the internal structure of the steel becomes compact, with high mechanical properties and strength, suitable for pipelines with higher pressure.
Casting flange: The metal is melted into a liquid and then poured into a mold for shaping, which has the characteristics of low manufacturing cost and high efficiency, suitable for pipelines with less pressure.

Importance of Flanges in Pipeline Connections

As a connecting and sealing part, the quality of flanges is directly related to the safety and reliability of the entire pipeline system. If there are quality issues in the production process of flanges, it may lead to leaks, causing economic losses, environmental damage, and even safety accidents. Therefore, the welding and production process of flanges are very important and must strictly control the quality.

Although flanges are just a small part of the entire product, pipeline, or machinery, their role is extremely important. CTT's flanges are precise and sturdy, ensuring people's use safety and reliability.