Abstract: A safety valve (1) has a first valve, and a second valve, a magnetic armature (3) moved by voltage applied to a coil (2). Movement of the armature (3) acts against a spring force of the first valve spring (5) and loosens the first valve body (4) from the first valve seat (6). The movement of the armature (3) subsequently acts against a spring force of the second valve spring (8) and loosens the second valve body (7) from the second valve seat (9). This frees a valve opening for a flowthrough of the gas flow. The flowthrough amount of the gas flow through the valve opening can be continuously controlled as a function of the voltage applied to the coil (2) between a closed position and a fully open position even in partially open positions.

Abstract: The invention relates to a radial fan impeller (1), in particular for using in gas fans with a steep fan characteristic curve, with the following features: with a plurality of blades (2) distributed around the periphery; viewed in the radial direction, the blades (2) extend from an inner inlet region (4) to an outer discharge region (6); the blades (2) extend axially, i.e.

Abstract: A blower for combustion air in a wall/floor furnace is provided that includes a blower housing (26), and blower wheel (27), with an air inlet (28) and an air outlet (29), and with a fuel feeder line (1) for fuel, wherein a mass current sensor (13) for determining the air mass current is located on the air inlet (28), which is functionally connected with a data processing device (4) and sends signals to the data processing device for calculation of a ratio of combustion medium to combustion air in dependence on a desired heating capacity.