The present invention regards an inline separator with a first pipe element (10) comprising a rotation-generating element (11) for the fluid flow downstream of an inlet (13) in the first pipe (10), a second pipe element (20) arranged at least partly inside the first pipe element (10), downstream of the rotation-generating element (11) and forming an outlet (25) for lighter density fluids, the first and second pipe elements (10, 20) forming an annular space (27) between an inner surface (15) of the first pipe element (10) and an outer surface (22) of the second pipe element (20), which annular space (27) is connected to a first outlet section (30) for heavier density fluids, wherein the second pipe element (20) is provided with a number of through-going openings (26) over at least a part of its length, the openings (26) leading to a second outlet section (31) for heavier density fluids, and both the first outlet section (30) and the second outlet section (31) are connected to a common container (40) with an outlet (41) for the heavier density fluids. The invention also related to a method for separating a fluid flow.