The most practical 6 solutions for flange corrosion are here

The integrity of the flange connection is critical to the delivery of fluid piping systems. Whether it is a piping system that transports chemical media (such as hydrocarbons) or a water supply line, flange connection leakage can cause serious environmental and economic impacts, and may even pose a huge safety hazard. If the flange is not protected, it can be exposed to corrosive environments or contaminated industrial atmospheres.