In conjunction with an Ex overpressure control ? e.g. as supplied by Stahl ? the conventional operating equipment is capable of being used in areas threatened by explosion. The intrusion of the explosive atmosphere is prevented by a permanent overpressure. An economic operation is ensured by a leakage rate below 20 l/min at 2 mbar test pressure. All enclosures are individually tested and supplied with an impermeability certificate. The result is a series of enclosure systems providing conditions for applications in the chemicals and petrochemicals industries, in the offshore sector and in the food industry.