In the spring of 2022, West Welding carried out a demanding condensate tank replacement at a pulp mill. Prior to starting the project, it became clear that the installation would present several challenges. Limited space, heavy components, and a tight schedule, all of which imposed their own constraints on the project execution.
“Typically, main condensate tanks are designed to last for the entire operational lifetime of the plant, so surrounding structures are not usually designed with replacement in mind. However, during a previous inspection, the regulatory authority recommended replacing the entire tank,” described Taneli Panttila, the project manager at West Welding, explaining the initial situation.
Minimizing plant downtime
The main condensate tank is a critical piece of equipment for the entire pulp mill.The production of pulp needs to be completely halted during its replacement. Therefore, due to financial reasons, the installation time needed to be minimized. The total time available for dismantling the old tank and commissioning the new one was limited to only 10 days.
“We approached the scheduling and space issues during the planning phase and determined that the best solution was to pre-manufacture the tank components as far as possible, taking into account that we could only lift pieces weighing up to 5 tons on-site. As a result, we decided to install the tank in four separate parts,” Panttila continues.
Thorough pre-planning ensured smooth installation
The installation process was well planned in advance, which helped to avoid any unpleasant surprises at the plant.
“The entire project proceeded as expected. We were prepared for everything, so there were no unexpected issues on-site. Occupational safety and quality matters were well taken care of, and we adhered to the schedule, making the project a successful one,” summarized Panttila.
In addition to quality and schedule considerations, safety of the workers on-site and the work of other employees at the factory was of utmost importance during the planning phase.
“Occupational safety always plays a central role. In addition to our own work, it is essential to consider the work of other factory employees during plant shutdowns and cooperate with them,” emphasized Taneli Panttila.
Around-the-clock work at the plant
Work at the pulp mill progressed around the clock through different phases:
- Installation work at the pulp mill’s boiler plant commenced with a pre-planned hauling route construction.
- Pipelines and walkways were temporarily dismantled from the installation site. (See 2nd image)
- The old tank was dismantled into pieces and transported along the hauling route.
- Factory’s own overhead crane was used to lift the pre-manufactured components for the new tank to the third floor.
- The new 100 cubic meter main condensate tank was welded in the limited space of the boiler plant within three days. (See 1st and 3rd images)
- After completing the main condensate water tank, West Welding conducted the necessary NDT (non-destructive testing) and tank pressure testing..
- Ten days later, the continuous production of pulp was once again ensured.