Abstract: In a filter, a rotatable connection flange with two kidney-shaped openings and a diametral web between the openings is located between the top part and bottom part of the filter. Rotating the connection flange allows the direction in which a gas flows through the filter element located in the filter housing to be reversed. In this way, the filter can be operated as a coalescence filter or as a dust filter by simply rotating the connection flange.

Abstract: A device for continuously fractionating a gas by adsorption, an in-service testing device in a processor-controlled adsorption drier system and a method for testing the operating capability of an adsorption drier system under the control of a processor, including two adsorbent beds connected to one another in a switching system, in which regeneration is performed by a flow of regeneration gas. The device has a gas inlet, a gas outlet and a bypass outlet feeding into a common functional block, which contains a line switching circuit, a first and a second shuttle valve and, optionally, other components. The in-service testing device and the device are so compact due to their respective structures that they can be integrated with one another requiring little space and having low assembly requirements. The testing method is configured to co-operate with the in-service testing device and the device, requiring only a few components for the application thereof.