The occurrence and overall solution of red rust on site

1. The hazards of red rust

1.1 Introduction of foreign objects;

1.2 The roughness of the red rust attachment part deteriorates;

1.3 Increase the working load of the filter;

2. Reasons for the formation of red rust

2.1 Main casues: High temperature during use (>80 ℃);

2.2 Secondary causes:

2.2.1 Material issues;

2.2.2 Oxidation of welding heat affected zone;

2.2.3 Introduction of other foreign objects (such as iron powder, dust, polishing consumables, etc.) during the installation

3. Standard process for removing red rust

3.1 Select the ratio, concentration, cleaning temperature, and cleaning plan of 1 # cleaning solution based on the degree of red rust accumulation in the product;

3.2 1 # cleaning solution for one-time cleaning to remove red rust;

3.3 Flushing and discharge;

3.4 2 # passivation solution regenerates a protective film on the surface of stainless steel;

3.5 Flushing and discharge

4. Confirmation of the removal effect of red rust

4.1 Chemical composition needs to be determined to ensure that it does not affect stainless steel and residues are removed

Cannot use so-called "confidential formula cleaning solutions" that even customers cannot know the ingredients;

4.2 The cleaning effect needs to be determined:

4.2.1 Visual inspection of visible areas;

4.2.2 "Invisible area" endoscopic examination;

4.2.3 Sampling and testing of iron content in the "hottest zone" by wiping;

4.3 The complete quality system documents include but are not limited to:;

4.3.1 Cause analysis;

4.3.2 Cleaning plan and report;

4.3.3 Cleaning agent compliance certificate;

4.3.4 Standard operating procedures and operating instruction diagrams;

4.3.5 Red rust prevention recommendation.