What are the details of purchasing stainless steel pipes

The material of stainless steel pipes is their very essence; choosing the right one is the cornerstone of ensuring the safety and durability of a project. Are you confused when faced with codes like 304, 316, and 201? These aren't just marketing numbers; they directly define the core performance of the pipe material: "corrosion resistance," much like the material's "immunity." The stronger the immunity, the less likely it is to "get sick" (rust and corrode) in complex environments.

First, how to choose the material based on the intended use of stainless steel pipes?
(1) For indoor dry decorative applications (such as indoor railings and furniture): consider the 201 series. Stainless steel pipes are relatively inexpensive and can meet basic decorative needs. However, please note that their corrosion resistance is weak; never use them in humid or outdoor environments.
(2) For outdoor structures, kitchen equipment, and municipal water supply pipes: 304 material must be selected. With its higher nickel content, stainless steel pipes are stable in complex atmospheres and water, making them a versatile food-grade and building-grade material. 
(3) For highly corrosive environments such as coastal areas, chemical plants, and pharmaceutical factories, stainless steel pipes of 316 and above are recommended. Stainless steel pipes with added molybdenum, based on 304, effectively resist chloride ion corrosion (such as seawater and acidic media), making them a sound investment for long-term safe operation.

Second, tips for self-inspection when purchasing stainless steel pipes.
The market is complex, and learning to make preliminary judgments is crucial:
1. Check the steel stamp on the stainless steel pipe: The pipe body must have a clear material stamp, such as "SUS304". This is the most direct proof of identity.
2. Request a quality certificate for the stainless steel pipe: Obtain a quality certificate from the supplier and verify the chemical composition. Reputable manufacturers provide traceable quality certificates for each batch of products.
3. Simple reagent test for stainless steel pipes: Prepare a stainless steel identification solution. 304 material will not change color significantly after 30 seconds, while 201 will quickly turn black.
4. Beware of low-price traps for stainless steel pipes: When the price of 304 stainless steel pipes is far below the market price, you need to be highly wary of their authenticity.