1. Thick-walled steel pipes should be submitted for inspection in batches, and the batching rules should comply with the regulations of the corresponding product standards.
2. The inspection items, sampling quantity, sampling locations, and test methods of thick-walled steel pipes shall be according to the regulations of the corresponding product specifications. With the consent of the purchaser, hot-rolled seamless thick-walled steel pipes can be sampled in batches according to the rolling root number.
3. If the test results of thick-walled steel pipes do not meet the requirements of the product standards, the unqualified ones should be singled out, and double the number of samples should be randomly selected from the same batch of thick-walled steel pipes to carry out the unqualified items. re-inspection.
If the re-inspection results fail, the batch of thick-walled steel pipes shall not be delivered.
If the following inspection items fail the initial inspection, re-inspection is not allowed.
4. For thick-walled steel pipes with unqualified re-inspection results, the supplier can submit them for inspection one by one; or they can undergo heat treatment again and submit a new batch for inspection.
5. If there are no special provisions in the product specifications, the chemical composition of thick-walled steel pipes shall be inspected according to the melting composition.
6. Inspection and inspection of thick-walled steel pipes should be carried out by the supplier’s technical supervision department.
7. The supplier has rules to ensure that the delivered thick-walled steel pipes comply with the corresponding product specifications. The purchaser has the right to conduct inspection and inspection according to the corresponding commodity specifications.