Abstract: In order to improve a method for warming up steam feed lines (1, 2) connected to steam turbine stages (9, 10, 11), in which method warming-up steam is directed through a section to be warmed up of a first steam feed line and a second steam feed line, this warming-up steam being directed through the first steam feed line in an operating flow direction (4), existing during the turbine operation, of the steam, and in which warming-up steam is discharged through bypass lines of the steam feed lines, in such a way that reliable and quick warming-up and draining of the steam feed lines is made possible, the disposal systems merely being designed for lower capacities, the warming-up steam, after being directed through the section to be warmed up of the first steam feed line, must be directed through a connecting line (5) to the second steam feed line, this connecting line being open during the warming-up, must then be directed through the section to be warmed up of the second steam feed line against the operating fl