How to solve the corrosion problem of flange forgings?

The integrity of the flange connection is critical to the pipeline system of the conveying fluid. Whether it is a pipeline system that transports chemical media (such as hydrocarbons) or a water supply pipeline, leaking flange connections will cause serious environmental and economic impacts, and may even bring huge potential safety hazards. If the flange is not protected and exposed to a corrosive environment or polluted industrial atmosphere, the corrosion rate will be very fast.

Flanges coated with color painting

Flanges coated with color painting

Due to the complex geometry of the flange connection,the gap corrosion between the two flange faces and the galvanic corrosion between different metals are very likely to seriously damage the integrity of the pipeline system. This article describes the solution to flange corrosion Several practical methods.

The ideal solution should take into account excellent corrosion protection performance and simple construction procedures, and should be suitable for flanges of various sizes and shapes, and can easily operate the bolts during maintenance. Solutions commonly used in the market today include:

1.Maintenance paint solution

Maintenance paint is a hard film that can be directly bonded to the substrate, generally an epoxy or polyurethane coating. There are many corners and edges of the flange. Due to the thinning effect of the edge, it is difficult for the conventional paint system to effectively cover the edge. Although the thickened coating will solve the problem of edge protection, it will also seal the fasteners and make it impossible to disassemble during subsequent maintenance. In addition, the coating will be damaged when the bolt is operated, and it must be repainted after maintenance. 

2.Mechanical solutions

The gap between the flange and the flange surface is mainly sealed by a protective cover and a clamp, usually a stainless steel or plastic material with a rubber sealing strip. This type of protection is less flexible and requires storage of covers or fixtures that perfectly match flanges of various sizes.

Flange coated with anticorroison coating and plastic cap for protection

Flange coated with anticorroison coating and plastic cap for protection

3.Hot melt plastic solution

Hot-melt plastics are essentially waxy fusible polymers heated at high temperature and sprayed onto the surface of the substrate through professional hot-melt equipment. The advantage of this protection method is that it can be remelted and reused, saving costs. However, this method also requires hot work, professional equipment and construction services. Although it can be reused, it is not easy to open and seal during maintenance.

Hebei Haihao Group can do all kinds of protection. We can do blue color painting,green color painting,black color painting,yellow color painting,zinc galvanized,coat with polyethylene,FBE coating and we can supply plastic cap for protect. So no need to worry about corrosion problem of our