Aluminium flanges are divided into pressure classes based on their maximum pressure capacity at a specific temperature. Typical classes include Class 125 and 150 for low to medium-pressure applications, Class 300 for more significant pressures, and Class 600 for even higher-pressure systems. Classes 900, 1500, and 2500 are utilised for exceptionally high-pressure applications. The system's operational characteristics, such as pressure and temperature, define the class. Compliance with ANSI, ASME, and ISO standards is critical for guaranteeing application compatibility and safety.

Aluminium flanges are divided into several types based on their design and application needs, such as the Weld Neck for high-pressure connections with a strong, leak-proof bond. Slip-on for easier alignment in low-pressure systems. Blind for sealing system ends, allowing for easy access; Threaded for environments where welding is not practical, allowing for easy attachment; Lap Joint for systems that must be dismantled frequently, providing ease of assembly; and Socket Weld for smaller, high-pressure systems, providing a strong bond and leakage prevention. Each kind has a different purpose, satisfying specific pressure, alignment, and assembly requirements in various industrial applications.

Aluminium flanges are coated primarily to prevent corrosion and increase their endurance. Despite its natural corrosion resistance, aluminium may rust over time if exposed to hostile conditions or chemicals. Coatings give an extra layer of protection, preventing corrosion and increasing the life of aluminium flanges, assuring their dependability in various industrial applications.