A chemical cleaning of a new boiler is called pickling, pre-commissioning- or pre-operational chemical cleaning. The purpose of a pickling of a steam boiler, before it is taken into operation for the first time, is to achieve the purity requirement for water and steam in the shortest possible time, and to form a protective oxide layer. A pickling makes the exposed surfaces clean, in order to form a comprehensive, compact and protective layer of magnetite when the boiler is put into operation. The quality of this protective layer and its ability to resist corrosion is critical for the lifetime and availability of the boiler.

A pickling shall remove impurities such as rust, shale, fat, sand, slag and other foreign objects, which originates from the manufacturing of the boiler.

How and if a boiler should be cleaned before commissioning is determined by a variety of factors such as heat flux density, pressure, demands on steam purity etc. Economic factors such as the cost for the cleaning and waste treatment, as well as savings through a technically less complicated and faster start-up of the boiler, must also be evaluated.

Wistrand generally perform pickling according to the standard VGB-S-513-00-2014-07-EN Internal Cleaning of Water-Tube Steam Generating Plants and Associated Pipework, modified according to local conditions.

In addition to the implementation and execution of the pickling, Wistrand also provides consultations within the field.