Gas that has been collected at the top of a receiving drum (3) as part of a radiator (1) is led to a storage tank (5) by a degassing pipe (4), where it is released to the atmosphere. The gas is pushed through the degassing pipe only if a pressure difference exists between the receiving drum and the storage tank. To create the pressure difference for low flow rates. A diaphragm with a flow dependant cross section is fitted to the gate. If the flow becomes very strong gas is carried over from the top of the receiving drum down to the gate with the diaphragm and the outlet from the radiator.
