Separation device or unit for separating liquid from an inlet flow which mainly contains gas, has a container or a pipe section with an outlet for gas from the container or the pipe section, an outlet for liquid from the container or pipe section and an inlet for the inlet flow to the container or pipe section. The device has a flow manifold arranged to receive and direct the inlet flow towards a porous pipe body extending towards the gas outlet and arranged to receive all or most of the inlet flow. Part of the flow is flowing through the tubular body to the gas outlet, while the remaining flow is flowing through the tubular body's porous wall, and an annular space including the volume between the tubular body and the container wall or pipe section is open for gas flow towards the gas outlet.