Because of the many types of stainless steel pipes, many of the standard brands are listed, and there are many non standard grades which are widely used in fashion. These brands have different performance and are widely used in fashion. These brands have different performance, so it is very difficult to choose the suitable grades of stainless steel pipes. It involves expertise in many disciplines such as materials science, corrosion science and engineering.
Before selecting stainless steel pipes, the use of stainless steel pipes and the use environment should be considered. For example: decoration used in general use of welded pipe, fluid transport generally seamless pipe, medical or kitchen to use sanitary stainless steel pipe, pressure use thick wall pipe; general indoor use of 200 series of materials, outdoor use of 304 and other materials, and in the acid and alkali local or coastal areas generally use more than 316 material.
When selecting steel pipes, it is necessary to make sure that the material is up to the standard. Take 304 material as an example: 1). from the price analysis, if the 304 material stainless steel pipe is even lower than the general price of the 301 material on the market, it is very likely that other materials are impersonating. 2). recognize whether the "304" mark on the pipe surface is required, and obtain the manufacturer's quality certificate as the voucher. 3). can be tested with acid reagent. After 304 seconds, 304 will not change color and 201 will turn black. 4). large quantities of purchased samples can be sent to the national authoritative Inspection Center for component analysis.
To see whether the color of the outer surface and the inner wall of the pipe is bright and smooth, whether the thickness is uniform or rough. The general welded pipe does not need to be checked, but the seamless steel pipe is produced by cold drawing or hot rolling. In the process of production, it is easy to produce uneven thickness and cracks in the pipe surface, and the surface roughness is generally seamless pipe without polishing treatment. If there is no special requirement on appearance, it does not affect the use.
When purchasing, we should select excellent products evaluated by the quality and Technical Supervision Bureau. Long term use of testimony and good reputation is the most direct and effective way to purchase customers.
Internal heavy skin, pitting, and rolling green line are often found in the rolling pipe. In general, these can not be avoided, but it does not affect the use, but we must choose as few as possible when choosing, especially the inner surface.