Forma Tank


The four scrubbers, each measuring 2.5M diameter x 11M high, had been de-commissioned a few years earlier as a result of the welded plastic structures continually leaking dangerous chemical products. However, an increase in site capacity required the scrubbers to either be replaced or repaired. Bringing these scrubbers back online would reduce odours being exhausted to the local environment.


Replacing the structure would entail major engineering and capital resolutions since they were contained inside the basement of a building, where other live services in/around/above this difficult-to-reach location. Additionally, this site was prone to very high H2S levels (possible fatalities).

Issues and success

HDPE is a notoriously difficult substrate to get any adhesion onto; Formatank developed a primer and technique for bonding GRP material onto the internal scrubber walls.

Specific GRP material choice was also very important since the contents of the scrubbers were sodium hypochlorite and sodium hydroxide solution with a working temperature of 5-25°C.

Despite repeated interruptions and evacuations on-site during installation due to high H2S alarms being triggered, Formatank completed the work in three weeks. The custom-made GRP liner was applied using the traditional hand-lay technique.

Ending and cost

The finished product offered a high-impact and corrosion-resistant material capable of accommodating structural movement.

The scrubbers now have an added life expectancy of over ten years. Without Formatank’s reconditioning these tanks, replacements would have been in excess of £1M.

  • Three weeks
  • Swansea, Wales
  • Water Industry
  • Relining four 2.5m diameter x 11m high HDPE scrubber tanks
  • £30,000
  • Tank life expectancy increased by Ten years
  • Saved the cost of brand-new tanks: £1M