Anti-corrosion sealing flanges are important components used for pipeline connections, featuring both anti-corrosion and excellent sealing performance. The following will introduce them from dimensions such as principle, material, type, and application:
Working principle
Sealing principle: Two flange plates are tightly connected by bolts, squeezing the flange gasket or sealing ring to fill the gap between the flange surfaces, thereby preventing the leakage of the medium in the pipeline. For instance, the ANSI flange forms a seal by the two sealing surfaces of the bolt squeezing the flange gasket against each other.
Anti-corrosion principle: It is mainly achieved by using anti-corrosion materials to make flanges or by applying anti-corrosion treatment to the flange surface. For instance, hot-dip galvanized flanges are made by immersing the flanges in molten zinc at around 500℃ after rust removal during the forming process, so that a zinc layer adheres to the surface of the steel components, achieving the purpose of anti-corrosion.
Material classification
Metal material
Stainless steel: Flanges made of stainless steel materials such as 304 and 316L have excellent corrosion resistance, high-temperature resistance and high strength, and can resist the erosion of various chemical substances. They are suitable for industries such as chemical engineering, food and medicine.
Stainless steel anti-corrosion sealing flange for hardware products
Carbon steel: It has a relatively low cost. After undergoing anti-corrosion treatments such as hot-dip galvanizing, painting, and plastic lining, its anti-corrosion performance can be enhanced. It is widely used in water supply and drainage, HVAC, and other fields.
Hot-dip galvanized carbon steel anti-corrosion sealing flange for hardware products
Alloy steel: It contains alloying elements such as chromium, nickel and molybdenum, and has higher strength and corrosion resistance. It is often used in pipeline systems with high-temperature, high-pressure and strongly corrosive media.
Non-metallic material
Plastics: Plastic flanges such as polytetrafluoroethylene (PTFE) and polypropylene (PP) have excellent corrosion resistance, chemical resistance and insulation. They are light in weight and low in price, but their strength is relatively low. They are suitable for some occasions with strong corrosiveness, low pressure and low temperature.
Polytetrafluoroethylene anti-corrosion sealing flange for hardware products
FRP: Composed of glass fiber and resin, it features excellent corrosion resistance, high strength and aging resistance, and can be used for pipe connections in industries such as chemical engineering, electroplating and sewage treatment.
FRP anti-corrosion sealing flange for hardware products
Common types
Plate flat welding flange: It has a simple structure and low cost, and is suitable for pipelines with relatively low pressure and large diameter. Its sealing surface form is mostly flat or raised. During installation, the pipe is inserted into the flange hole for welding.
Plate type flat welding anti-corrosion sealing flange for hardware products
Necked flat welding flange: The neck is relatively short, and the welding with the pipe is fillet weld. It has certain strength and sealing performance, and is suitable for medium and low pressure pipelines.
Necked flat welding anti-corrosion sealing flange for hardware products
Necked butt-weld flange: The neck is relatively long, and the welding with the pipe is a pair weld seam. The welding quality is high, the sealing performance is good, and it can withstand high pressure and temperature. It is often used in pipelines carrying high pressure, high temperature, and toxic, flammable, and explosive media.
Necked butt-weld anti-corrosion sealing flange for hardware products
Socket welding flange: The pipe is inserted into the socket hole of the flange for welding. It is suitable for small-diameter pipes and has good sealing performance, but is not suitable for occasions where frequent disassembly is required.
Anti-corrosion sealing flanges for socket welding of hardware products
Application field
Chemical industry: Used for transporting various corrosive chemical raw materials, acid and alkali solutions, etc., flanges are required to have excellent anti-corrosion and sealing performance to ensure the safety and stability of the production process.
In the oil and gas industry: During the processes of oil extraction, transportation and processing, a large number of anti-corrosion sealing flanges are needed to prevent oil and gas leakage and ensure the normal operation of the pipeline system.
Water supply and drainage industry: It is used in urban water supply and drainage pipeline systems to prevent water leakage and pipeline corrosion, and to extend the service life of pipelines.
The food and beverage industry: It has high hygiene requirements. Anti-corrosion sealing flanges made of stainless steel and other materials can ensure the quality and safety of food and beverages and prevent the medium in the pipeline from being contaminated.
