The TUNNEL washers are designed for cleaning in continuous and are typical for multi-stages process and high throughput using water base detergents. They are based on the "pass-through" principle and are normally employed in the production lines but for their flexibility can also be used for limited production. The system offers many possibilities and a wide range of conveyors allow, practically, limitless applications: continuous or indexing motion, belt or chain type, for single parts or baskets or pallets. The TUNNEL washers can be configured for one-stage or multi stages applications, for interprocess or precision cleaning with drying and protection of the workpiece. The process can be developed according to the cleaning requirements also using specific techniques. Drying can be done by an "air knife" or by hot ventilation in closed loop or the combination of both. All the operations are controlled by PLC with complete monitoring of functions and parts in process.