scope:

This specification is to be used for the revalidation of Submarine First Level & sea wetted castings made of Nickel Aluminium Bronze manufactured to DGS 8520, DGS 348 or Defence Standard 02-747 Part 1, 2 or 4 which have had service use involving contact with sea water.

Revalidation in accordance with this specification is to establish the extent of any selective phase corrosion, the acceptability of any weld repairs and the wall thickness following final dressing to remove corroded regions. This information will allow the Design Authority to determine the suitability of the casting for future use. It is additional to the normal inspections and tests applied to the Submarine First Level castings, e.g. radiography and surface dye penetrant examinations.

Part 1 of this Defence Standard covers the policy for the recording and updating of Nickel Aluminium Bronze castings fitted in submarines to meet the First Level Quality Assurance requirements in accordance with SSP 25.

Part 2 of this Defence Standard is to be used for the validation of all Submarine First Level castings made of Nickel Aluminium Bronze manufactured to Defence Standard 02-747 Part 1, 2 or 4. It is to be used to establish a baseline of data for any weld repairs, wall thickness measurements and the integrity of the casting at manufacture.

Part 4 of this Defence Standard is to be used for in-service inspections carried out outside of the Long Overhaul Period.