Characteristics of food hygiene grade stainless steel pipe
We often encounter the saying of sanitary stainless steel pipe in our life. It is actually a kind of steel pipe that can be used in food. This sanitary stainless steel pipe is mainly used in the production equipment or production assembly line for making some food. In addition, it can also be used in beverages, alcohol, bioengineering and so on.
Because the sanitary stainless steel pipe is used in making a series of food items, the safety standard of sanitary stainless steel pipe is very strict. What about the production standard of sanitary stainless steel pipe? In the following small series, users will be introduced in detail.
1、 Characteristics of food hygiene grade stainless steel pipe
For the standard of sanitary stainless steel pipe, the requirements are mainly for the surface finish, oil prohibition and passivation layer of stainless steel pipe.
1、. Surface finish: polish the internal and external surfaces of the steel pipe to make the steel pipe surface bright; That is what we often call a mirror. It is mainly to prevent the fluid substances in the pipe from forming hanging wall in the pipe, which is easy to pollute and form blockage in the pipe after a long time.
2. Passivation layer: after polishing, the steel pipe shall be immersed in the passivation tank, and the surface of the steel pipe shall be oxidized with acid passivation solution to form a passivation layer, so as to achieve the anti-corrosion effect of the steel pipe.
3. Oil forbidden degree: after passivation, oil forbidden cleaning shall be carried out to remove the oil stain on the steel pipe surface. After completion, the oil analyzer shall be used for inspection. It mainly prevents the oil pollution of the pipe wall itself from polluting the fluid substances in the pipe.
2、 Executive standard for sanitary pipe
ASTM a270 - American Standard
Din 11850 - European standard
QBT / 2467 - stainless steel pipe for food industry
matters needing attention:
1. Many manufacturers only have internal polishing after internal leveling, but lack of bright annealing. Although the weld bead can not be seen after polishing, it will be easy to corrode from the weld after a long time.
2. When purchasing products, users should never superstitious about bright products. The real food pipe pays attention to the Ra value (roughness) of the inner wall, not throwing it and waxing it to make it bright.
The standard of sanitary stainless steel pipe has a very strict specification, and there is a detailed guideline for the requirements of each step of production. Both at home and abroad have their own standards. However, many manufacturers have saved a lot of steps in order to save costs. In this way, there is no problem with the surface of sanitary stainless steel pipe, but it will be found after inspection. Therefore, when purchasing sanitary stainless steel pipe, users must pay attention to choosing genuine products with quality assurance and brand.