{"id":8492,"date":"2026-08-14T10:41:09","date_gmt":"2026-08-14T03:41:09","guid":{"rendered":"https:\/\/giaanh.vn\/?post_type=kien-thuc&p=8492"},"modified":"2026-10-08T14:32:23","modified_gmt":"2026-10-08T07:32:23","slug":"part-7-materials-for-special-conditions","status":"publish","type":"kien-thuc","link":"https:\/\/giaanh.vn\/en\/knowledge\/material-selection-for-special-operating-conditions\/","title":{"rendered":"Part 7: Material selection for special operating conditions"},"content":{"rendered":"

For most locations, the selection process can begin with operating conditions and proceed through sequential screening based on temperature, abrasion, impact, and corrosion<\/strong>.<\/p>\n

However, some applications cannot begin with this sequence.<\/p>\n

If a location has requirements concerning food contact, extremely high temperatures, highly corrosive chemicals, or fire resistance<\/strong>, compliance requirements and applicable documentation need to be checked first. A material may be entirely suitable in terms of technical properties but still be unsuitable for use if the mandatory certification or documentation for the specific application is missing.<\/p>\n

Therefore, under special operating conditions, the range of materials needs to be narrowed down according to the mandatory application requirements<\/strong> before proceeding to evaluate material properties.<\/p>\n

1. Four conditions that may change the selection sequence<\/span><\/h2>\n

Four groups of conditions need to be considered separately:<\/p>\n\n\n\n\n\n\n\n\n
Condition<\/strong><\/th>\nWhy it needs to be checked first<\/strong><\/th>\n<\/tr>\n<\/thead>\n
Food contact<\/strong><\/td>\nMaterials lacking appropriate certification or documentation may not meet the application requirements<\/td>\n<\/tr>\n
Extremely high temperatures<\/strong><\/td>\nTemperatures may exceed the operating ranges of most conventional material groups<\/td>\n<\/tr>\n
Highly corrosive chemicals<\/strong><\/td>\nSuitability must be evaluated according to the specific chemical, concentration, and temperature<\/td>\n<\/tr>\n
Fire-resistance requirements<\/strong><\/td>\nThese are separate safety requirements that cannot be directly inferred from a material’s heat resistance<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

In these cases, the selection sequence needs to become:<\/p>\n

    \n
  1. Identify the mandatory application requirements<\/strong><\/li>\n
  2. Verify the required certifications and documentation<\/strong><\/li>\n
  3. Narrow down the material groups that meet the requirements<\/strong><\/li>\n
  4. Continue screening according to actual operating conditions<\/strong><\/li>\n<\/ol>\n

    The difference lies in the first step. The list of materials eligible for consideration has already been restricted before mechanical properties are examined in detail.<\/p>\n

    2. Determine early whether the location falls under special operating conditions<\/span><\/h2>\n

    The assessment can begin with three questions:<\/p>\n

      \n
    1. Does the material come into direct contact with the product?<\/strong><\/li>\n
    2. Does the peak temperature at the location exceed 550 \u00b0C?<\/strong><\/li>\n
    3. Is the location subject to the plant’s fire-resistance requirements?<\/strong><\/li>\n<\/ol>\n

      If the answer to any question is \u201cyes,\u201d the applicable requirements need to be checked before proceeding with material selection.<\/p>\n

      For chemical environments specifically, the following need to be identified:<\/p>\n