BS ISO 21173:2019,Submersibles – Hydrostatic pressure test – Pressure hull and buoyancy materials.BS ISO 21173:2019 pdf free download.
BS ISO 21173:2019 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.
BS ISO 21173:2019 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.
BS ISO 21173:2019 is not applicable to submarines and other submersibles parking or operating underwater for more than one week.
BS ISO 21173:2019 provides a unified specification for the hydrostatic pressure test method applicable to the pressure hull and buoyancy materials of submersibles to confirm that their pressure resistance performance is normal prior to assembly.
4.6 Test record
All test checks shall be recorded, and relevant reports shall be filled in.
4.7 Specification
The factors and terms in this document should be used when the design is not specific. When a design specifies other factors and terms, these should be considered, and the final decisions agreed with the designer and the recorded for use.
5 Detailed requirements
5.1 Preparation before the tests
Prior to testing,the the integrity and appearance of the pressure structure shall be checked, and parameters
such as dimtensions and weights of the pressure structure shall be measured.
5.2. 2 Test pressurization and depressurization rates and holding time
The process of the hydrostatic pressure test is to simulate the hydrostatic external pressure applied to the pressure structure during diving, operating at the maximum working depth, and surfacing of the submersible. The test pressurization rate shall not be less than the pressure change rate caused by the diving speed of the submersible. The holding time at the maximum working pressure shall not be less than the design operation time at the maximum working pressure. The depressurization rate shall not be less than the pressure change rate caused by the surfacing speed of the submersible. The holding time at a pressure higher than the maximum working pressure during the test may be adjusted according to actual conditions.