ISO 21173:2019

This document specifies a test method for the hydrostatic pressure test for pressure hull and buoyancy materials of submersibles. The test sequence comprises a tightness test and the hydrostatic pressure test itself. It can also include continuous pressurization and depressurization tests, long-term static load and cycling external pressure tests.
This document is applicable to the pressure structure of manned submersibles and unmanned submersibles, including the pressure hull, its accessories (such as viewports, hatches and connectors) and buoyancy materials. The long-term static load and cycling external pressure tests are only applicable to buoyancy material.
This document is not applicable to submarines and other submersibles parking or operating underwater for more than one week.