Abstract: A control apparatus for a liquid medium including a body portion provided with flow channels. The body portion includes an inlet for the medium, an outlet for the medium to an apparatus that the medium is conducted to, a return point for the medium returning from the apparatus, and a discharge point through which the medium is discharged from the control apparatus. A flow control valve and flow and pressure measuring devices are arranged after the medium inlet in the flow channels of the body portion. A pressure control valve for controlling the pressure in the flow channels between the flow control valve and the pressure control valve is arranged after the return point. For safety reasons, a pressure relief valve is arranged in the channel system of the body portion provided by the flow channels between the flow control valve and the pressure control valve, the relief valve being arranged to open as the pressure exceeds a certain allowed value.

Abstract: The invention relates to a combination of a helmet or a protective mask and a respirator that can function under ram pressure. The helmet's chin arch (1) contains a face element (4), a filter (3) and inhalation and exhalation valves (5,6). The air can, for instance, flow through the apertures (2) in the chin arch (1) to the respirator. The face element (4) can be moved by means of a lever (11) in accordance with the pressure caused by the air stream.

Abstract: This invention relates to a mounting piece for the suction hose of a central vacuum cleaning system. In order to prevent objects that could possibly clog the suction piping from getting into the piping, there is on the inner wall (2) of the mounting piece (1) at least one rib (3) pointing inwards from the inner wall which prevents objects that would clog the suction piping (5) from getting into the suction piping (5). The surface of the rib (3) or ribs (3) that meet the flow are preferably inclined towards the central axis of the mounting piece.