A device in connection with a pipe separator. The pipe separator comprising an extended tubular body (1) with a diameter that is principally the same as or slightly larger than the diameter of the inlet pipe (3) of the pipe separator. A gas manifold (2) is arranged in connection with the inlet pipe. The manifold (2) includes a number of vertical degassing pipes (7), which are connected to the supply pipe (3) immediately ahead of the inlet to the separator and which end in an overlying, preferably slightly inclined gas collection pipe (6). The manifold is designed so that the gas will be diverted up through the vertical degassing pipes and collected in the gas collection pipe (6) for return to the outlet pipe after the separator or transported onwards to a gas tank or gas processing plant or the like.