Which standard is often cited for liquid penetrant testing procedures?

The correct choice is the standard ASTM E165, which is widely recognized and cited for liquid penetrant testing procedures. ASTM E165 provides comprehensive guidelines for both the methods and practices employed in liquid penetrant testing, a nondestructive testing (NDT) technique used to detect surface-breaking defects in non-porous materials.

This standard outlines essential elements such as the types of penetrants and developers, the processes for surface preparation, the application of the penetrant, and the methods for interpretation of the test results. These guidelines help ensure consistency and reliability in the application of liquid penetrant testing across various industries.

The other standards mentioned have their specific scopes: ISO 9712 pertains more generally to the certification of personnel for nondestructive testing; ASME Section V covers various NDT methods, including liquid penetrant testing, but is more focused on the requirements for the qualification of procedures and personnel as per ASME codes; ASTM E286 is related to the evaluation of penetrant materials and may not be as comprehensive in detailing testing procedures as ASTM E165. Consequently, ASTM E165 stands out as the primary standard for detailing the actual procedures for liquid penetrant testing.