Abstract: A method and apparatus for handling the fluids in a two-phase flow pipeline system. The gas-liquid flow stream is fed into a separator in which the gas is separated from the liquid. The gas is removed upwardly from the seaparator through a control valve. The liquid is removed downwardly from the lower portion of the separator. The liquid level in the separator is detected and a controller effects opening or closing of the control valve whereby the rate of flow of the liquid out of the separator is controlled. An elongated accumulator is in fluid communication with both the liquid outlet of the separator and the outlet of the control valve. The liquid flowing out of the separator is fed into the elongated accumulator loop which has previously been filled with gas. A free piston is positioned in the accumulator loop ahead of the liquid to separate the accumulated liquid from the gas in the accumulator loop.