WHY DO STAINLESS STEEL PUMPS RUST?

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Customers usually think that stainless steel pumps do not rust and that a rusty pump is not a stainless steel pump. When there are brown rust spots (blotches) on the surface of a stainless steel pump, customers assume that there is something wrong with the steel. In fact, this is a one-sided misconception based on a lack of understanding of stainless steel. Stainless steel will rust under certain conditions.

There are many forms of damage to the surface film.

1. The stainless steel surface has dust containing other metal elements or particles of dissimilar metals attached to it. In humid air, condensation between the attachment and the stainless steel connects them into a miniature cell, which leads to an electrochemical reaction and damages the protective film, which is called galvanic corrosion.

2. Organic juices attached to the surface of stainless steel (such as melon vegetables, noodle soup, spit etc.) constitute organic acids in the presence of water and oxygen. Over the long term, the organic acid will reduce the corrosion of the metal surface.

3. The adhesion of the stainless steel surface contains acids, alkalis, salts and other substances (such as alkaline water, lime water splashed on the decorative wall), resulting in local corrosion.

4. In contaminated air (such as the atmosphere containing large amounts of sulphide, carbon oxides and nitrogen oxides), the formation of sulphuric acid, nitric acid and acetic acid liquid spots in the presence of condensate, resulting in chemical corrosion.

These conditions can cause damage to the protective film on the surface of stainless steel and lead to corrosion.

Therefore, to ensure that metal surfaces are bright and corrosion free, we recommend that

1. decorative stainless steel surfaces are cleaned and scrubbed frequently to remove attachments and eliminate external factors that cause modifications.

2. 316 stainless steel should be used in coastal areas, which is resistant to corrosion from seawater.

3. The chemical composition of some stainless steel tubes on the market does not meet the corresponding national standards, nor does it meet the 304 material requirements. Therefore, it can also lead to rusting, which requires users to carefully select products from reputable manufacturers.