Hyperbaric testing concerns the application of external pressure to a product. The product is housed within a pressure vessel/chamber which acts as the barrier to retain the external pressure around the test subject.
The primary reason for doing this is to replicate actual conditions an assembly will see in installed life, meaning the external pressure will first and foremost validate the structural integrity of the component. Secondary to that, any ingress of pressure into the component would highlight a leak path(s) which may compromise areas such as sealing arrangements or welded joints.
The principle of hydrostatic testing is very similar to hyperbaric testing in that this will also verify structural integrity and any leak paths, as well as utilising water as the test medium. The fundamental difference is that a hydrostatic test concerns the internal pressurisation of a component, rather than subjecting it to external pressure. The likes of a product sealing arrangement will still very much but scrutinised but with pressure effectively pushing ‘in-to-out’ rather than ‘out-to-in’.
Certain components may be subjected to a hydrostatic and hyperbaric test simultaneously e.g. subsea pipeline equipment. These products would typically feature primary, secondary and tertiary sealing barriers to withstand excessive levels of internal and external pressure.