In all kinds of pipe corrosion resistance of stainless steel flange is the best, because stainless steel flange and oxidant inactivation. On the surface form a layer of tough dense CR rich protective oxide film on Cr2O3, so as to effectively prevent the oxidation reaction of further. Stainless steel flange corrosion usually for the stainless steel flange pipe wall thinning, local pits and pock, stainless steel flange does not like carbon steel that uniform corrosion, without the use of the protective coating, stainless steel flange corrosion detection method is magnetic flux leakage method and ultrasonic testing method.
One, the stainless steel flange standard definition of the thickness of the following:
1, effective thickness – is the nominal thickness minus the corrosion margin C2 and the thickness of the negative deviation of the thickness of the steel.
2, nominal thickness – is the thickness of the design thickness of D plus a negative deviation of the thickness of the C1 after the steel standard specification, that is, the thickness of the profiled flange pattern.
3, design thickness – is the sum of the thickness and corrosion allowance.
4, the thickness of the calculation is calculated by the formula of the thickness, when needed, should be included in the required thickness of other loads.
Two, there are seven stainless steel flange derusting process need to understand:
1, first remove rust surface visible dirt, and then use solvents or cleaning agents to remove oil.
2, with the shovel knife to a large area of corroded steel.
3, with scraper and wire brush to remove the side corner of the corrosion.
4, use the file to remove the welding slag and other protrusions and various burrs.
5, the use of cloth and steel wire brush to clean up.
6, with a clean cloth, but also can be used to clean the solvent and the solvent to clean and timely painting primer.
7, pay attention to for yet fail the toughness of the coating may be preserved, and hit the old wool paint surface with emery cloth, grinding film defect into the axe and clean after direct painting.
Finally, but also to understand the common sense of stainless steel flange vacuum seal, mainly rubber seal, metal seal and magnetic fluid seal. Among them, the metal seal can meet the requirements of ultra high vacuum, but there are the following disadvantages: metal seal ring elastic, great sealing force, the repeated use of very poor, flange sealing surface and the edge roughness and the fitting accuracy requirement is high, sealing ring and the flange material thermal expansion coefficient difference is big enough to cause the local deformation caused by leakage.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)