How should the surface of the pump casing of the stainless steel corrosion-resistant centrifugal pump be treated?

The main products of ATACH Pump Factory are corrosion-resistant pumps, especially stainless steel acid pumps and 

alkali resistant pumps. 

How should the surface treatment of the stainless steel corrosion-resistant centrifugal pump be designed to balance 

aesthetics and durability? 

The surface treatment process of the stainless steel pump shell needs to take into account corrosion resistance, 

surface smoothness, coating adhesion, 

and long-term working reliability. According to ATACH's usage feedback, the following treatment methods are

 recommended:

1. Recommended surface treatment processes:

•      Grinding treatment

Remove oxide scale, rust, and impurities, increase surface roughness, and enhance the adhesion of subsequent

 coatings, suitable for both inner and outer surfaces of the pump shell.

•      Fine polishing

Make the surface smoother, reduce medium adhesion and corrosion points, especially suitable for high cleanliness

 industries such as food and pharmaceuticals.

•      Acid washing and passivation treatment

Form a dense chromium oxide (Cr₂O₃) passivation film on the surface of stainless steel through chemical methods, 

significantly enhancing resistance to pitting and crevice corrosion, which is a standard corrosion prevention method 

for stainless steel.

•      Electro-polishing (optional)

Utilize electrolysis to further improve surface smoothness and strengthen the passivation film, suitable for high-purity

 or highly corrosive medium environments.

2. Optional surface coating protection (depending on the working conditions)

If the medium is highly corrosive or there is erosion and wear, the following coatings can be considered:

•      Epoxy resin coating

Good corrosion resistance and high mechanical strength, suitable for general corrosive media.

•      Polytetrafluoroethylene (PTFE) coating

Excellent chemical inertness, resistant to strong acids, strong alkalis, and high temperatures, suitable for extreme 

corrosive environments.

•      Non-metallic lining or wear-resistant composite coating (such as in desulfurization pump scenarios)

For conditions with solid particles or cavitation, ultra-polymer carbon composite materials and other new protective

 layers can be used.

⚠️ Note: If the pump shell is 304 stainless steel, in environments with chloride ions (such as seawater, salt water), 

it is recommended to upgrade to 316L or duplex stainless steel, and combine the above surface treatment to ensure

 reliability.

3. Maintenance and care suggestions

•      Regularly rinse the external surface of the pump shell with clean water to avoid accumulation of dirt.

•      Apply oil to unassembled components during storage to prevent rust.

•      Avoid using chlorine-based cleaners to prevent damage to the passivation film.

In summary, "grinding + acid washing and passivation" is the most basic and effective surface treatment scheme 

for the pump shell of  stainless steel corrosion-resistant centrifugal pumps; in harsh working conditions, coatings

can be stacked or higher-grade materials can be selected.