Defence Standard 02-872 documents the mandated procedures and requirements for the management of Submarine Sea Water Wetted First Level castings made from Nickel Aluminium Bronze (NAB) to DGS 8520, DGS 348, NES 747 Part 1, 2 or 4 or Defence Standard 02-747 Part 1, 2 or 4.

This Defence Standard 02-872 Part 2 is to be used for the VALIDATION of Submarine First Level castings made from Nickel Aluminium Bronze to Defence Standard 02-747 Part 1, 2 or 4, which are to have service use involving contact with sea water.

All NAB castings in First Level Quality Assured systems, either for current platforms as specified in SSP 25(Obsolescent standard suitable for use in support of legacy equipment only), or for future platforms categorised as First Level under Def Stan 02-207 with validation and revalidation specified in the SOQR, must be examined prior to installation to confirm conformance with specific procurement and design requirements. This validation procedure in accordance with Part 2 of this Defence Standard is part of the overall procedure for First Level Nickel Aluminium Bronze casting management.

Validation is used to establish the integrity of the casting at manufacture and generate the baseline data for wall thickness and any weld repairs. It certifies that the Nickel Aluminium Bronze casting meets the Submarine First Level Quality Assurance requirements in accordance with the SOQR (or QASOR). Correctly conducted validation provides the information necessary to allow subsequent revalidation of the casting to determine the suitability for further submarine service.