The construction of data centres and the need for cooling systems to dissipate the heat generated by servers processing data 24 hours a day continue to boom, with market growth expected to continue in the future. The interim between cooling system installation and data centre startup are strategies for keeping cooling water systems in like-new, corrosion-free condition during hydrotesting and dry layup.
Hydrotesting with VpCI-649
Cooling water systems and any piping network designed to handle fluids must be hydrotested to check for leaks and pressure durability before they are used. Unfortunately, this critical step also leaves behind residual moisture that can incite corrosion and related problems before operation starts. This can lead to clogging in pipes and chillers at startup or deterioration and leakage of the system wall if left undetected. A solution is to add VpCI-649 to the hydrotest water. VpCI-649 combines contact and vapour phase corrosion inhibitors in a liquid formulation that does not contain nitrites, phosphates, or chromates. Treated hydrotest water can be captured and reused for multiple hydrotests on different pieces of equipment. Those also facing molybdate restrictions can opt for VpCI-649 MF, which uses a PTSA tracer, in place of molybdate, for detection of corrosion inhibitor concentration. As VpCI-649 circulates through the system in the hydrotest water, it leaves behind a corrosion inhibiting film that continues to protect the piping after the system is drained. No further removal is needed before commissioning.
Dry layup of chiller bundles and other isolated chambers
After the chiller has been installed but prior to piping completion, larger, isolated void areas like the chiller bundle should undergo dry layup with the cooling tower frog. This Cortec water treatment ‘animal’ consists of a water-soluble bag containing vapour phase corrosion inhibitor powder. The product is easy to apply, with little or no surface preparation required. Once the bags are placed in the end of the chiller bundle or other enclosed area, the film should be slit open to release the corrosion inhibiting vapours before closing all openings to the void area. As time passes, these vapour phase corrosion inhibitors diffuse throughout the enclosed space, adsorbing on metal surfaces in the form of a protective molecular layer that inhibits the corrosion reaction, in the presence of moisture. There is no need to remove the cooling tower frog at the end of the layup period. When the chiller is turned on and cooling water is flushed through the system, the cooling tower frog will dissolve in the make-up water.
