For Q355B square tube and industrial stainless steel tube, although they are both stainless steel tubes, there are still some differences between them. Needless to say, the gap in the application field determines the implementation standards, process requirements and surfaces of the two.
The main difference between Q355B square pipe and industrial pipe is that the heavy metal content of Q355B square pipe is much lower than that of industrial pipe. According to the standard GB 31604.34-2016 “Determination and Migration Determination of Lead in Food Contact Materials and Products of National Food Standard”, it is required that the dissolved lead content of Q355B square pipe under acetic acid immersion is less than or equal to 0.05; while industrial pipes, such as Markov, are not suitable for stainless steel. Lead content is not specified.
The obvious difference is on the surface. The surface of Q355B square pipe must be grade BA, which is a bright surface; while industrial pipes have no requirements on the surface, but the surface is often rough, the key is to have high corrosion resistance. For the Q355B square pipe that is in direct contact with food, the finish inside the pipe is very important. However, the inner wall of the tube needs to be polished and bright annealed to make the inner wall smoother. If there is a liquid medium in it, clogging can be prevented.
Post time: Jul-19-2022