Ex jest normą okreslajaca przydatnosc urzadzenia do zatosowania w warunkach zagrozenia wybuchem (dyrektywa EWG 94/9/EC).
urzadzenia dopuszcozne do pracy w takich warunkach maja specjlany znak dopuszczenia Ex.

This instruction gets special meaning when using pumps which are corresponding to a device category according to the directive 94/9/EC, however, are driven by a motor which does not meet these criteria. Then it might be that the pump has been provided with the EX-sign but the unit must not be used in areas with explosion hazard due to the non EX-admitted motor. So the operator has always to pay attention to the conformity with the directive 94/9/EC of all used components of the pump unit.