The printing mark you mentioned is only the function of a mark, that is, to explain what standard your pipe is produced with, what steel grade it is, and so on. To judge whether it is qualified or not, it is necessary to do specific tests with reference to standards, such as whether it meets a series of tests such as chemical elements, mechanical properties, physical properties, chemical properties, nondestructive testing and so on. All tests that meet the standards are qualified products.