First, take 304 material as an example: when selecting steel pipes, the material must be determined to meet the standard.
1. From the price analysis, if 304 stainless steel pipe is even lower than the general price of 301 material on the market, it is likely to be other materials;
2. Identify whether the tube surface is stamped with the word "304", and ask for the manufacturer's quality certificate as a certificate;
3. Can be tested with acidic reagent, 30 seconds after the material 304 does not change color, 201 turns black;
4. Samples can be sent to the national authoritative testing center for component testing when purchased in large quantities.
Second, the rolled pipe often appears inside heavy skin, pitting, and rolling green line, in general, these can not be avoided, and basically do not affect the use, but in the purchase must choose as little as possible, especially to check the inner surface.
Third, the purchase should choose the excellent products assessed by the quality and technical supervision bureau. In the customer has a long time to use the witness and good reputation is the most direct and effective method of purchase.
Fourth, watch whether the color of the outer surface and the inner wall of the tube is bright and smooth, whether the thickness is uniform or rough. Generally welded pipe this basic need not check, and stainless steel seamless pipe is produced by cold drawing or hot rolling, improper operation in the production process is easy to produce uneven thickness, pipe surface cracks and other phenomena, and the surface rough is generally seamless pipe without polishing treatment, if there is no special requirements for the appearance does not affect the use.
Fifth, before selecting stainless steel seamless pipe, it is necessary to consider the use of stainless steel pipe and the use environment. Such as: decoration generally use welded pipes, fluid delivery is generally used seamless pipes, medical or kitchen to use sanitary stainless steel pipes, pressure use thick wall pipes; Generally, 200 series materials can be used indoors, 304 and other materials need to be used outdoors, and 316 or more materials are generally used in acidic and alkaline places or coastal areas.
