With the aim of optimising performance and function, Ruwac has revised its Gas Ex vacuum cleaner series and implemented numerous detail improvements. For the DS 1220 and DS 2520 series – each in the gas Ex version for zones 1 and 2 – these include the use of new, energy-efficient three-phase AC motors which have been developed for operation in gas Ex zones and are approved accordingly. Other components, such as electrical equipment, have been replaced by new series. The DS 1220 and DS 2520 are gas Ex vacuum cleaners for continuous operation in industrial applications even under demanding conditions. According to the manufacturer, they offer high reliability and safety even in critical applications such as the collection of combustible dusts and the extraction of insulating, i.e. non-conductive, dusts. A further important feature of these vacuum cleaner series is the modular design, which allows an application-related selection of the equipment. The vacuum cleaners can then, for example, be operated up to temperature class T5 or with filters of dust class H according to EN 60335-2-69.