Ultra high pressure (UHP) washing is a highly-effective and environmentally-friendly cleaning method using water jets to remove old coating systems and industrial dirt and contamination, without the use of potential contaminants such as detergents or grit.

Leading rope-access specialist Skyriders recently deployed UHP to clean the top part of a large tank, which is exposed to the harsh elements, and therefore subject to the worst weathering, for a major petrochemical producer in Mpumalanga.

The scope of work for Skyriders was to deploy UHP at 2 800 bar in order to wash the tank and prepare the surface, and then to apply a specific protective coating system. This consisted of a primer and an intermediate coating, followed by the final two coatings.

“The client, which has stringent health and safety and quality standards, had a documented specification for the application that we had to adhere to rigorously at all times,” Skyriders marketing manager Mike Zinn comments. This was necessary to guarantee the integrity of the entire protective system.

Major industrial customers such as petchem and chemical plants and refineries, among others, often have separate budgets for both maintenance and access. “On this specific project, for example, we were able to prove to the client that our per-square-metre rate, which is all-inclusive of both access and maintenance, represents a significant cost- and time-saving,” Zinn asserts.

He adds that Skyriders’ holistic approach to access and maintenance generally translates into a 20% to 25% budget saving for its clients, in addition to benefits such as enhanced health and safety and guaranteed quality of any work undertaken.

The traditional means of cleaning such large tanks is grit blasting, which leaves behind a residue that itself needs to be cleaned up. This sand can also pose a safety risk during the cleaning process, as the tank remains operational during maintenance so as not to impact on productivity. The high-pressure water used in UHP, on the other hand, simply evaporates.

Skyriders intends to expand the scope of its UHP service offering, as this cleaning method is ideal for major industrial structures as diverse as smokestacks, silos, and storage tanks. “It is not only an important value-added service, but is an integral part of the turnkey access and maintenance solutions we can offer,” Zinn concludes.