AC flexible oily fiber anticorrosion sealing oil band system is provided with good corrosion performance to be used external anticorrosion of steel in bad sea water condition, at present, it is widely used long term anticorrosion of various equipment protection in air, underground and underwater. The system is provided with good convertibility and flexibility to form any shape, so it is especially applied to anticorrosion of different equipment such as flange, valves and pipe fittings T-joints, water tanks, underground tans, piping, machines, steel structures, steel piles, cast iron sockets in oil and water conveyance in petrochemical industry, shipbuilding and other industries. With construction experience of more than 50 years, the anticorrosion system with oil tape as foundation is more durable and safer with easier operation than traditional painting. It is most suitable for anticorrosion of profile equipment, such as flange, valve and so on. Previously, we often ignore anticorrosion of flange; we only paint some oil on flanges which however would be etched due to long term exposure to moisture and corrosion conditions, thus resulting in serious accidents and losses. The system is used to get rid of erosion possibility of work piece. Also, a convenient overhaul can restore the system for further use, in cases of emergencies. Thus routine maintenance cost is saved. From the view of long term or short term economic interest or social effect, or from the view of equipment’s long use, this system is the most applicable. The system includes four parts: seal paste, putty (mortar), tape and protection band. This is based on the principle of hydrophobic oil and oily to constitute oily protection layer with a few continuous layers on the surface of work piece, so that the equipment is always to stay in seal condition of oil film which is impossible to be peeled or cured, especially in moisture or under water or in ground environments. The flexibility feature of the system without curing, hardening and cracking is able to adapt thermal expansion and shrinkage of work piece for long term seal protection. The system is able to resist erosion of inorganic acid, alkali and salt and has good electric insulation nature. The operation of AC oily fiber anticorrosion tape is easy to operate; it can be operated in water and moisture surface directly, which is other kinds of anticorrosion can’t accomplish. No volatile toxic and harmful components are in the system in conformity with strict international requirement for environment protection. Anticorrosion protection shall cover Steel structure splash in sea ports and humid condition Steel structure in salty fog and damp condition Embedded valve and flange of gas pipeline Valve, flange fittings and piping in yard and station Valve in valve room of long piping Long high pressure piping and valve Profile fittings in oil storage tank area Piping and flange in chemical factory