What does the presence of residual water after a hydrotest indicate about potential issues?

The presence of residual water after a hydrotest raises concerns primarily because it may lead to microbiological corrosion. After a hydrostatic test, the vessel is filled with water to test its integrity, but if water remains trapped inside, it creates an environment that can support the growth of bacteria, particularly if organic materials are present. These bacteria can produce corrosive byproducts, which can significantly deteriorate the material of the vessel over time, leading to structural weaknesses and potential failure. This phenomenon emphasizes the importance of thorough drying and cleaning after hydrotesting to mitigate the risk of such corrosive activities occurring.

While hydrotesting itself is critical for ensuring the integrity of pressure vessels, having residual water signifies that additional steps are necessary to prevent long-term maintenance issues. This understanding is crucial for maintaining operational safety and extending the service life of the equipment.