Stainless Steel Flange Corrosion-related Knowledge

The corrosion resistance of stainless steel flanges in all kinds of tubes is the best, because stainless steel flanges can be deactivated with oxidants, forming a layer of tough dense chromium-rich oxide protective film $literal on the surface, thus effectively preventing the further occurrence of the oxidation reaction. Stainless steel flange corrosion is usually manifested as stainless steel flanges of the tube wall thinning, the emergence of local pits and pitting, stainless steel flange will not be like carbon steel, uniform corrosion, use without protective coating, stainless steel flange corrosion detection method is leakage magnetic flux and ultrasonic testing.

Stainless steel Flange Standard The definition of thickness is as follows:

1. Effective thickness-is nominal thickness minus corrosion margin C

2. And thickness of steel thickness negative deviation.

3. Design thickness-is calculated thickness and corrosion margin of the sum.

4. Calculate the thickness-is calculated according to the chapter formula thickness, should be counted into other load required thickness.

Second, stainless steel flange and seven major derusting process need to know:

1. Remove rust before removing all kinds of visible dirt on the surface, and then use solvents or detergents to remove oil.

2. With tungsten carbide shovel shovel to large area rust.

3. With the scraper and wire brush to remove the corners of the rust.

4. With a file to remove the solder slag and other highlights and a variety of burr.

5. Clean with emery cloth and wire brush.

6. With a clean rag, can also be used dishcloth dip solvent for cleaning and timely painting primer.

7. Pay attention to the toughness of the film has not yet expired, can be retained, and used emery cloth to beat the old paint surface, the film defects will be polished into ax-shaped, clean directly after painting.

Finally, also understand the stainless steel flange vacuum seal common sense, mainly has the rubber seal, the metal seal and the magnetic liquid seal. Among them, metal seals can meet ultra-high vacuum requirements, but there are the following disadvantages: The metal seal ring elasticity is poor, need very big sealing force, the repetition usage is very bad, the flange seal surface and the knife edge roughness and the match precision request is high, the seal ring and the flange material’s thermal expansion coefficient difference is big, easily causes the local distortion to cause the air leakage and so on.