Pickling and passivation of the inner surface of helium cooling tanks and exchangers - in Sweden

5. 8. 2022

Our company is the only one in the Czech Republic and Slovakia to provide the service of pickling and passivation directly at the customer's site or at the installation using a mobile pickling workplace, including the capture and ecological disposal of rinse water. We hold all the necessary authorisations, decisions and certificates for carrying out work in this way. We carry out standard pickling and passivation of tanks, structures, piping systems and weldments, as well as special work to achieve oxygen or pharmaceutical cleanliness.

In June 2022 we carried out work for Centrum výzkumu Řež, s.r.o. and Nuvia, s.r.o. at the site of the European Spallation Source (ESS) research centre under construction in Sweden. This involved pickling and passivation of the internal surface of the helium cooling tanks and heat exchangers.

Circulation pickling is most often used when cleaning exchangers or tanks already installed as part of a larger technology, when dismantling is not possible or when the technology cannot be shut down for a longer period of time. As standard, the pickling and passivation with water flushing is carried out after each step, the last flushing is carried out with demi-water until a neutral pH is reached - the procedure is therefore also suitable for food processing plants. It is important that the entire tank or exchanger area can be completely vented and drained. Otherwise, air bubbles may form or incomplete rinsing of the pickling agents may occur, resulting in a reduced quality of work, and the subsequent use of the pickled part may also be affected.

The ESS complex is a unique building, the only one of its kind in the world. As a scientific facility, the safety of all workers is paramount. A number of documents, regulations and plans had to be prepared before work began, and strict safety measures had to be observed on site. ESS staff were pleasantly surprised by the execution of the work, during which there were no leaks or excessive odours; however, this is standard practice for us. As this is a research centre, the emphasis was also on high quality. Each tank was thoroughly inspected with an endoscope by ESS inspectors upon completion of the work - the handover was smooth and without complaint.

Technically, this project was not exceptional for us. However, we have verified that we can handle this type of order in terms of logistics, documentation and communication.