A pipe cutting system (40) and method for cutting a helically wound steel pipe while the pipe is being moved in a direction (12) of its longitudinal axis uses a plasma torch (50) supported to be reciprocally movable parallel to the longitudinal axis and at an orientation relative to the pipe so that a plasma jet emitted by the plasma torch is directed upwardly toward the pipe. The plasma torch is arranged move at a speed that is synchronised with a speed at which the pipe is being moved in the direction of the longitudinal axis. The pipe is rotated during cutting so that the plasma torch circumferentially cuts the pipe while the pipe is being moved.