Firstly, before the selection of 304 stainless steel pipe, you should consider its usage and environment. We often use weld pipe for decoration, seamless steel pipes for fluid delivery, sanitary stainless steel pipes for medical or kitchen, thick-walled steel pipes for pressure. 200 series material can be used for indoors and 304 can be used for outdoors. In the alkaline or coastal areas, level over 316 materials are generally used.

Secondly, the selection of 304 stainless steel pipes must be standard. From the price analysis, if the 304 stainless steel pipe is lower than 301, then you should carefully identify. It is likely replaced by other materials. Recognize whether the surface has the material words "304", and check the quality certificate from manufacturer. Using acid reagent for test, 304 stainless steel pipes will not change color after 30 seconds but 201 will getting black. If you need to purchase in bulk, you'd better take some samples to the national authority for component testing.

Thirdly, observe the outer surface and inner wall color if it is bright and smooth, the thickness is uniform or rough. Generally, welded pipe need not to check. However, seamless steel pipe is manufactured by cold drawn or hot rolling, the surface is to crack with improper operation in the production process. If the surface is rough, it generally means seamless steel pipes have not been polished.