Case study: Preservation of heat exchangers

Heat exchangers, whether new or refurbished, have complex geometry which makes them prone to corrosion. Traditional washing and preservation is difficult.

Zerust products make preserving heat exchangers easy with highly concentrated VCI capsules on the inside and VCI plastic on the outside.

The VCI on the inside of the casing penetrates all cavities, as well as the inside of the pipes and protects against corrosion. UV resistant shrink plastic provides an additional protective barrier. Desiccant such as silica gel between these layers minimizes moisture and facilitates long-lasting protection.

As always with corrosion protection, it is important that the surfaces are clean and dry for the preservation to work optimally. Old, corroded exchangers must be cleaned first so that salts, ions and old rust are removed. We have our own procedures and chemicals for this. Here are a couple of examples. Get in touch if it is relevant.

Exchangers have very challenging isometry, which makes preservation demanding. There is a lot of metal surface in relation to the total volume. Thus, far more VCI molecules are required than if the object were an empty tank. In addition, the molecules must travel through long and narrow tubes by 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 shrink-wrapped for outdoor storage.

Heat exchangers that are to be stored indoors can be packed with the yellow VCI plastic without using outdoor shrink plastic.