The name PPR elbow is a relatively broad general term. If it is specific, it will be divided into industrial-grade stainless steel and sanitary-grade stainless steel pipe fittings. PPR elbow, stainless steel tee, stainless steel four-way, stainless steel head and stainless steel are also derived. Diameter pipe (eccentric size head), etc.; because of the effect of "nickel" element, it is collectively referred to as "stainless steel" pipe fittings
Industrial-grade pipe fittings are generally used in industry, and the surface does not need special treatment, while sanitary-grade stainless steel pipes are mainly used in beverage, food, beer, bioengineering and other production equipment and assembly line factories, so both the surface and the inner wall must be Strictly deal with it to meet the national standard. It is mainly for the surface finish, oil-proof degree and passivation layer of stainless steel pipe fittings;
The first is the surface finish, which is what we often call mirror. The inner and outer surfaces of the steel pipe are polished to make the surface of the steel pipe bright, mainly to prevent the fluid material in the pipe from forming a wall in the pipe, which is easy to contaminate and cause blockage in the pipe for a long time;
The next step is the passivation layer. After polishing, the steel pipe needs to be put into the passivation tank for immersion, and the surface of the steel pipe is oxidized with an acidic passivation solution to form a passivation layer, so as to achieve the anti-corrosion effect of the steel pipe;
The last step is the oil-free degree. After the passivation is completed, the oil-free cleaning is carried out, and the oil pollution on the surface of the steel pipe must be removed. After the previous steps are completed, it needs to be checked with a grease analyzer. The purpose is to prevent the oil pollution of the pipe wall itself from contaminating the fluid substances in the pipe, and truly meet the requirements of food grade;
Therefore, whether stainless steel pipe fittings rust is not only related to the need to add "nickel" elements during production, but also has a lot to do with the details of the production process, so it is also called "sanitary pipe fittings".