Abstract: A method for controlling the operation of a steel refining converter of the type having bottom tuyeres, each tuyere consisting of a center jet surrounded by annulus jets is disclosed. Controls are provided for blowing oxygen through the center jets and a fuel gas, such as propane, through the annulus jets during the refining step. Purging gases, such as nitrogen and compressed air, are blown through the jets during other parts of the steel making process. By means of switching circuits, the flow of each selected set of gases is established before the previously selected set can be cut off, one set of gases is automatically substituted for another if there is a loss of pressure at the tuyeres, nitrogen is substituted for oxygen and fuel if the flow of either of the latter two gases falls below a predetermined value and tilting of the converter to an upright position is prevented unless there is adequate pressure in the tuyeres.