In a method for a safety valve plus such a safety valve, the safety valve has the form of a valve body axially displaceable in a cavity with an inlet on either side of which are arranged outlets, whereby liquid and/or gas flow takes place from the inlet and past the valve body via a flow path to the outlets. On the valve body side, the flow path is provided with a structure that raises the friction in relation to the liquid and/or gas flow between the inlet and outlets.