The PVHO rules are written for a water depth of several hundred meters. However underwater windows in ship hulls and in semi submarines are located close to the water surface. For this application PVHO should not be applied. A more interactive approach between the classification society in charge and the marine engineers should be preferred. This approach should include comparisons with similar vessels, applied examination of static of the window structure, material certificates and the like.
QPA stands for Qualitätsprüfung bei Auslieferung. The QPA will result in an acceptance test certificate for individual acrylic blocks in accordance to DIN EN 10204. The QPA test is part of a set of regulations provided by our manufacturer of acrylic blocks. The whole set of certificates enables Hydrosight to provide products according to Germanischer Loyd's classification and building rules. It can be used to certify products to ASME/PVHO. PVHO is mostly used in marine (especially submarine) applications. The QPA test results are provided for special purpose windows, similar to those listed in chapter "Hydrosight Service Contracts"