The subject matter of this specification can be embodied in, among other things, a fluid flow conditioning apparatus that includes a linear fluid conduit having a first tubular body defining a major axis and extending from a conduit inlet to a conduit outlet arranged opposite the conduit inlet, and configured with a predetermined flow geometry to define a linear fluid flow path along the major axis, a fluid inlet non-parallel to the linear fluid flow path, a first fluid flow conditioner configured to receive fluid flow, condition fluid flow, and redirect conditioned fluid flow along the linear fluid flow path along the major axis, a second fluid flow conditioner configured to receive fluid flow from the linear fluid flow path along the major axis, redirect fluid flow away from the linear fluid flow path, and condition fluid flow.