The main materials of flanges for medium and low pressure pipe fittings include carbon steel, cast iron, and stainless steel.

Carbon steel is a common flange material with advantages such as good corrosion resistance, mechanical properties, and weldability. It can withstand high pressure and temperature, and is often used as a manufacturing material for medium and low pressure pipe flanges. Cast iron flanges are usually suitable for low-pressure, low-temperature, and general fluid and gas transportation pipelines and equipment. Although their strength is relatively low, they are relatively inexpensive and suitable for use in some low-pressure engineering.

In addition, stainless steel flanges also occupy a certain market share in the flanges of medium and low pressure pipe fittings. Stainless steel material has excellent rust resistance, especially its outstanding acid and high temperature resistance, and is often used in pipeline systems in industries such as chemical and pharmaceutical industries. Although the use of stainless steel flanges is costly, their performance advantages are highlighted in specific environments, such as high temperature, high pressure, and strong corrosive media.

Overall, the material selection of flanges for medium and low pressure pipe fittings depends on the specific usage environment and engineering requirements. Different materials have different performance characteristics and need to be selected according to actual situations. When selecting flanges, in addition to considering the material, it is also necessary to consider factors such as their specifications, connection methods, sealing performance, etc., to ensure the safe, stable, and efficient operation of the pipeline system.