Case study: Preservation of heat exchangers
Heat exchangers, whether new or refurbished, have complex geometry that makes them prone to corrosion. Traditional cleaning and preservation are difficult.
Zerust products make the preservation of heat exchangers easy with highly concentrated VCI capsules on the inside and VCI plastic on the outside.
The VCI inside the casing penetrates all cavities, as well as the interior of the tubes, to protect against corrosion. UV-resistant shrink wrap provides an additional protective barrier. Desiccants such as silica gel between these layers minimize humidity and facilitate long-term protection.
As always with corrosion protection, it is important that surfaces are clean and dry for the preservation to function optimally. Old, corroded exchangers must undergo cleaning first so that salts, ions, and old rust are removed. We have specific procedures and chemicals for this. Here are a couple of examples. Contact us if this is relevant. 
Exchangers have highly challenging geometry, which makes preservation demanding. There is a great deal of metal surface area in relation to the total volume. Thus, far more VCI molecules are required than if the object were an empty tank. Furthermore, the molecules must travel through long and narrow tubes via gas diffusion. Powerful VCI chemicals are required, such as our ActivPak VCI powder.
The heat exchanger housing and components can also be protected with Zerust VCI products: connection points are covered with VCI plastic and VCI capsules are placed inside the housing.
The entire heat exchanger is then packed in Zerust VCI plastic and shrunk for outdoor storage.
Heat exchangers intended for indoor storage can be packed with yellow VCI plastic without the use of outdoor shrink wrap.
