Cold Water Tank Replacement

This is one of those jobs that plays to the strengths of the Kimpton team. It’s a project to replace a 40,000 gallon (180m3) cold water tank on an industrial site. Our aim was to minimise disruption to the production plant it supplies, by working to agreed hours, with scheduled mini-shutdowns.

The old tank was fibreglass and the integrity of the seals between panels had started to break down. In addition, cleaning the tanks, which needs to happen annually, was a major job. The issue was the lack of low-level access, which meant it had to be treated as a confined space and therefore fully scaffolded before cleaning could begin.

The job began by draining and decommissioning the tank. A large access hole could then be cut so we could work safely inside the tank. The job of dismantling the panels involved the removal of nearly 3,000 individual nuts and bolts. We previously replaced the cold water tank at the Capital Building.

The existing pipework removed was all 6″ copper pipework – so of a very large scale.

With this removed we could begin to install all of the new bracketry and prefabricated stainless steel Type 316L Schedule 10S pipework, ready for the tank.

With the preparation completed, the installation of the new GRP tank began. Because of changing demand and more efficient water management on site, it was smaller at 25,000 gallons (96m3) and also met more recent legislation in terms of low-level access to make ongoing cleaning far easier.

The tank was chemically cleaned and chlorinated before being filled from the newly installed pipework. With all of this done, the tank was brought online.

The water level in the new tank is measured by a sonar which feeds the information into a BMS. The inflow of water is delivered through an equilibrium ball valve. As a further back-up, there is an early warning 3/4″ pipe to warn of potential overflows with an additional 6″ overflow near the top of the tank.

To prevent freezing anywhere in the system there are also two immersion heaters inside the tank and trace heaters on the incoming pipework, again linked to the BMS.

The job looks great, works perfectly and was completed in under five weeks.