API 5L specification requires strictly for API 5L X70 PSL1 steel pipe production and quality

The API 5L specification requires API 5L X70 PSL1 steel pipe manufacturer's license and maintains a comprehensive index of approved manufacturers.

This means that at the request of a potential manufacturer, the API will send auditors to the factory to ensure that they are able to meet the standards to produce API 5L X70 PSL1 steel pipe.

This would be similar to a franchise, but the API does not benefit financially from the API 5L X70 PSL1 steel pipe factory and does not accept any responsibility for mill behavior or product performance. API 5L does not have its own pipe size table. Instead, like the ASTM standard, it returns to ASME B3610 for nominal pipe size.

The API 5L specification is generally clearer about the limits of dimensional deviation (pipe verticality, straightness, hockey sticks, reaming pipes), while the ASTM standard is more ambiguous. Therefore, API 5L requirements are generally considered as the basis for mill tolerances, whether API 5L specifications are described in the API 5L X70 PSL1 steel pipe purchase order or not.