In industrial fluid transportation and thermal temperature control systems, flanges are core connecting components that ensure pipeline docking, sealing and pressure bearing. As standardized general accessories, they undertake key functions including pipeline connection, pressure bearing, medium sealing and detachable maintenance, and are widely used in heat transfer, refrigeration, chemical and fluid equipment, serving as the fundamental guarantee for stable operation of the entire process system.

A complete flange consists of a flange disc, bolt holes, sealing face and pipe connection section. It realizes rigid connection between equipment and pipeline ports through uniform bolt compression and matching sealing gaskets. Compared with integral welded connection, the biggest advantage of flange connection is detachability and reusability. Equipment disassembly, inspection, cleaning and replacement can be completed without pipeline cutting, greatly reducing later operation and maintenance costs for industrial equipment and adapting to scenarios requiring regular maintenance and working condition adjustment.

According to structural differences and process adaptation, mainstream industrial flanges include plate flat welding flanges, neck butt welding flanges and integral flanges. Plate flat welding flanges feature simple structure and high cost performance, suitable for low-pressure, normal-temperature and clean medium working conditions. Neck butt welding flanges disperse stress through transitional neck structure with higher welding strength, excellent deformation resistance and fatigue resistance, adapting to medium and high pressure as well as alternating high and low temperature working conditions. Integral flanges are integrally forged with equipment ports, possessing ultra-high structural rigidity for harsh processes with high-pressure and high-risk chemical media.

The sealing face determines the comprehensive performance of flanges. Common types include raised face, male and female face, and tongue and groove face. Different sealing structures match distinct pressure grades and medium characteristics: raised face flanges are highly versatile and easy to disassemble for general civil and light industrial scenarios; male-female face and tongue-groove face flanges precisely limit gasket displacement, prevent gasket deviation and falling off caused by high-pressure fluid impact, and effectively avoid medium leakage, ideal for transporting corrosive, high-pressure, flammable and explosive fluids.

Material selection directly affects the corrosion resistance and pressure resistance of flanges. Carbon steel flanges deliver outstanding cost performance for clean water and conventional circulating media; stainless steel flanges have excellent rust and acid-base corrosion resistance for long-term service in seawater, salt solutions and mild chemical environments; special alloy flanges are customized for heavy corrosion and ultra-high pressure conditions, meeting high-end process demands in fine chemical, oil and gas, and special refrigeration industries.

In thermal equipment supporting applications, flanges not only connect pipelines, but also balance stress at equipment ports, relieve stress loss caused by fluid impact and operational vibration, and protect equipment interfaces from deformation and leakage. With standardized dimensions and pressure grades, flanges feature strong universality and interchangeability, becoming indispensable basic connectors for industrial fluid systems.