Hydrotesting of industrial pipes, valves, and other vessels presents an irony. While hydrotesting is done to ensure that no leaks are present and that the vessel will hold up under expected operating pressures, it also raises the risk of corrosion by introducing moisture to the system.
The same water that proves the vessel is not compromised can be the very cause of corrosion that deteriorates the metal and leads to leakage over time. Cortec® claim to provide an excellent answer with the VpCI®-649 Series for hydrotesting.
Corrosion Protection for Hydrotesting
VpCI®-649 is a unique concentrated liquid formulation that combines contact and Vapor phase Corrosion Inhibitors. These inhibitors form a molecular protective layer on metal surfaces below and above the water level. VpCI®-649 protects both ferrous and non-ferrous metals, including copper, steel, galvanized steel, aluminum, and cast iron. VpCI®-649 does not contain nitrites, phosphates, or chromates—a characteristic that helps minimize disposal concerns. It is also available in a molybdate-free version (VpCI®-649 MF) for use in regions with molybdate restrictions. VpCI®-649 BD contains an organic-dispersing agent, and VpCI®-649 Winterized provides protection against product-freezing during storage.
Hydrotesting for Long-Term or Short-Term Corrosion Protection
When dosing VpCI®-649, users must decide how long they want corrosion protection to last and adjust concentration and dwell time accordingly. Options range from protecting the metal only during hydrotesting to protecting the metal for up to two years after hydrotesting. Extended preservation is often desired when the metal component must either undergo a shipping or storage period before it will be put into use. In some cases, hydrotesting with VpCI®-649 is done specifically for the purpose of mothballing. This is possible because of the film forming quality of VpCI®-649, which leaves behind a corrosion inhibiting layer on the metal surface and typically does not need to be removed before putting the vessel into service.
