Factory Heating: Hot Well, Hot Water Tank Lining

We were recommended to this client by a major UK industrial boiler manufacturer, as its hot well tank had badly corroded. The carbon steel hot water tank was used as part of the factory’s hot water system and also as a steam condensate return tank. It had been recently installed but within six months had suffered extensive corrosion, cratering and pitting below the water line.

Challenges

  • Extensive corrosion, cratering and pitting had quickly occurred.
  • At the current rate of corrosion, replacement or repair was essential.
  • The craters and pitting in the steel were 2.5mm – 3mm deep.
  • Due to the deep pitting, it was necessary to apply a resin based screen over the entire floor and 1m up each wall.


Our Solution

Having assessed the rapid wear, we recommended the repair of the tank using a high temperature resistant tank lining system. The tank lining system used was a high temperature tolerant, solvent free, glass flake reinforced epoxy system. This system, with its cross-linking glass flake reinforcement, imparts outstanding protection to metal and concrete substrates, forming a durable barrier resistant to abrasion, erosion and thermal shock.

All internal surfaces of the tank underwent abrasive grit blasting to SA2.5 and the prepared surfaces were then extensively cleaned using an industrial vacuum cleaner. A high temperature tolerant epoxy primer coating was initially applied and a resin based screen repaired the damaged pitting. Multiple coats of high temperature resistant epoxy resin tank coating was applied liberally to achieve a complete and even coverage. On completion, we rigorously tested the treated surface for coating thickness and absence of micro-porosity in the tank lining.


Hot well, hot water tank lining work completed

Results

This tank lining system has outstanding corrosion and chemical resistance. It was specifically designed for use in the most aggressive combinations of high temperature and chemical environments. It can be used for potable and non-potable water applications in immersed conditions of up to 125°C and dry condition up to 200°C. By restoring the tank lining, we were able to avoid the costly replacement of a very young tank, whilst extending its practical working life by an anticipated fifteen plus years. To avoid any disruption to the site, we were able to work flexibly to complete the work on time and in accordance with our client’s schedule.