For many years progressing cavity pumps, peristaltic pumps, and macerators manufactured by Allweiler AG have fulfilled the requirements for use in potentially explosive gaseous atmospheres when used properly. But now – since end 2008 – they are also certified for use in dust-laden explosive atmospheres.
The ATEX certificate confirms that Allweiler pumps now fully comply with EU directive 94/9/EC “Explosion Protection' when used in accordance with specifications. This directive requires proper documentation for all new installations and initial start-ups of equipment in areas with potentially explosive atmospheres.
Allweiler fulfilled the safety requirements for dust-laden, potentially explosive environments without any design changes. Their pump series have long been used in potentially explosive, gaseous atmospheres. Allweiler pumps are also equipped with monitoring devices. These measures immediately detect disturbances even in dusty atmospheres and avoid problems like dry running, overload conditions, and ultimately impermissible warming of the pump surface.
The EU directive likewise addresses both electrical and mechanical hazards associated with operating pumps in potentially explosive areas. As a result, it is not adequate to simply power a pump unit with a motor certified according to the Ex directive. The mechanical part of the machine must also have documented ignition protection. Specifically, the pump unit may not reach the ignition temperature of the potentially explosive atmosphere, whether during operation or disturbance or due to excessive wear or mechanical failure.
Progressing cavity pumps, peristaltic pumps, and macerators produced by Allweiler meet precisely these requirements. This is particularly true of equipment group II, categories “2” and “3” of the directive, i.e. for use in frequently explosive and briefly explosive gaseous or dust-laden atmospheres (zones 1, 21, 2, and 22). Unlike gaseous atmospheres, dusty atmospheres are not associated with temperature class limitations.