Polyester: Laminated polyester tanks are durable and easy to repair. A non-stick protective coating helps protect the tanks from the inside. Traces of welding/joints to other equipment may reduce cleaning efficiency.
High-density polyethylene (HDPE): These tanks are highly resistant to chemicals. The absence of seams improves cleaning efficiency. These tanks can also be formed into blocks by blow-moulding, thereby avoiding any seams.
The tank's shape must comply with a crucial factor: ease of cleaning. Preference should therefore be given to tanks with no blind spots (which retain the spray liquid and are difficult to reach with rinsing nozzles), welded seams or any areas presenting irregularities or a coarse texture. The tank outlet for draining should ideally be located as low as possible on the filling tank and be positioned so that there are no blind spots restricting the evacuation of the spray mixture or the rinsing water.
Finally, the filling tank should ideally be equipped with a deep chamber with a small surface area in contact with the air. This prevents air from entering the tank when the tank is gradually emptied of spray solution during treatment.
The rinsing tank can be integrated into the filling tank or be separate and adapted to the system. The rinsing tank allows the spray circuits and the filling tank to be cleaned without the user being in contact with the treatment residues. The rinsing tank should be about 10% of the total volume of the filling tank.
The application system can also be equipped with a gauge to monitor the filling of the tank, one or more washing nozzles connected to the rinsing tank, and a stirrer that keeps the spray mixture moving to avoid any sedimentation of the less soluble components. Some installations, as is the case at Chateau Latour, enable better quality homogenization of the spray liquid thanks to a dedicated filling space.