1) The logo should be prominent and durable, with clear, standardized characters that are resistant to fading.
2) The logo should at least include the following: manufacturer's name or trademark, product standard number, steel grade, product specifications, and traceability identification number. For highly precision-welded steel pipes, additional main performance indicators and size accuracy levels can be included.
3) Markings can be applied using methods such as spray printing, stamping, roller printing, printing, sticker application, or (hanging) tags, allowing the supplier to choose one or more marking techniques.
4) The marking paint or black water used on the surface of stainless steel pipes must not contain any harmful metals or metal salts, such as zinc, lead, or copper.
5) Seamless steel tubes with an outer diameter of not less than 36mm should be marked starting not less than 200mm from the end of the tube, and the marking method described in item 3 should be applied individually. Steel tubes with an outer diameter less than 36mm may not be marked individually.
6) Welded steel pipes for low-pressure fluid conveyance, galvanized welded steel pipes, wire conduit, electric welding pipes for general use, special-shaped section welded steel pipes, and complex-shaped seamless steel pipes may not be marked individually.
7) Alloy steel pipe markings should include the furnace number and batch number after the steel grade.
8) Pipe connectors for geological and oil pipes should have a steel grade (grade) mark.
9) Threaded steel pipes with left-hand threads should have a standard number followed by the character "左" or the English letter "L."
Each bundle of steel pipes should be tagged or hung with at least 2 labels or tags, and each pipe with markings can be tagged or hung with 1 label or tag. The label or tag should at least include the following information: manufacturer's name or trademark, product standard number, steel grade, product specifications, heat number (except for products where the product standard does not specify the chemical composition), batch number, weight (or number of pipes), and manufacturing date.
