When 304 stainless steel pipes leave the factory, they need to be pickled and passivated, which is what we often call ordinary acid whitening. However, sometimes users ask for re-degreasing of the pipes? As far as stainless steel pipes are concerned, the more reasonable degreasing should be done on site, that is, after all the pipes are installed, degreasing should be carried out in the entire pipeline system. Degreasing treatment also needs to meet certain testing requirements:


1) Use ultraviolet light with a wavelength of 320 to 380nm to inspect the inner wall of the pipeline. There should be no grease fluorescence.

2) Wipe the inner wall of the pipe with clean and dry white filter paper. There should be no traces of oil on the paper.

3) Or use degreasing solvent to detect that the grease content does not exceed the client's requirements.

4) Other relevant technical indicators proposed by the client.


The chemical cleaning and degreasing process of stainless steel oxygen pipelines standardizes the construction process of oxygen pipeline cleaning and degreasing, greatly improves the internal cleanliness of oxygen pipelines, and is a reliable guarantee for the safe and efficient operation of oxygen pipelines. It deserves the attention and promotion of stainless steel pipe manufacturers.

To sum up, why 304 stainless steel pipes need to be degreased and deoiled? This is related to the medium inside. Generally, ordinary chemical pipelines are not degreased and deoiled. If oxygen is used inside, then it needs to be done. Skim and remove oil.