Arrangement (ARG) through which a process fluid (PFF) is able to flow along a main flow direction (MFD), comprising an impeller (IMP) which is rotatable about an axis (X) in a direction of rotation (RTD), and an upright diffuser (DFF) which is situated downstream of the impeller (IMP) and is equipped with guide vanes (VNE), wherein the impeller (IMP) has an inlet (INI) for a substantially axial inflow and has an outlet (EXI) for a substantially radial outflow, wherein radially and axially extending rotor blades (BLD) are arranged between a wheel disc (HWI) and a cover disc (SWI) of the impeller (IMP) and delimit impeller channels (ICH) with respect to one another in a circumferential direction (CDR), wherein the diffuser (DFF) extends substantially radially along a main flow direction (MFD), wherein the diffuser (DFF) has an axial cover disc side (SWS) and an axial wheel disc side (HWS), which delimit between them an axial channel width (SAC) of the diffuser (DFF), wherein the diffuser (DFF) has a diffuser inlet (IND) for a substantially radial inflow and has a diffuser outlet (EXD), wherein guide vanes (VNE) extending axially along a vane height direction and radially along a throughflow direction are arranged between the wheel disc side (HWS) and the cover disc side (SWS) of the diffuser (DFF) and delimit guide vane channels (HCN) with respect to one another in a circumferential direction (CDR), characterized in that a profile curvature angle (VBA), which is an angle between a tangent (TLV) to a mean line (BWL) in the inlet edge region and a tangent (TTV) to the mean line (BWL) in the outlet edge region (TEA), is smaller on the cover disc side than on the wheel disc side, wherein the profile curvature angle (VBA) is measured in the mathematically positive sense, proceeding from the tangent (TLV) to the mean line (BWL) in the inlet edge region. comprising an impeller (IMP) which is rotatable about an axis (X) in a direction of rotation (RTD), and an upright diffuser (DFF) which is situated downstream of the impeller (IMP) and is equipped with guide vanes (VNE), wherein the impeller (IMP) has an inlet (INI) for a substantially axial inflow and has an outlet (EXI) for a substantially radial outflow, wherein radially and axially extending rotor blades (BLD) are arranged between a wheel disc (HWI) and a cover disc (SWI) of the impeller (IMP) and delimit impeller channels (ICH) with respect to one another in a circumferential direction (CDR), wherein the diffuser (DFF) extends substantially radially along a main flow direction (MFD), wherein the diffuser (DFF) has an axial cover disc side (SWS) and an axial wheel disc side (HWS), which delimit between them an axial channel width (SAC) of the diffuser (DFF), wherein the diffuser (DFF) has a diffuser inlet (IND) for a substantially radial inflow and has a diffuser outlet (EXD), wherein guide vanes (VNE) extending axially along a vane height direction and radially along a throughflow direction are arranged between the wheel disc side (HWS) and the cover disc side (SWS) of the diffuser (DFF) and delimit guide vane channels (HCN) with respect to one another in a circumferential direction (CDR), characterized in that a profile curvature angle (VBA), which is an angle between a tangent (TLV) to a mean line (BWL) in the inlet edge region and a tangent (TTV) to the mean line (BWL) in the outlet edge region (TEA), is smaller on the cover disc side than on the wheel disc side, wherein the profile curvature angle (VBA) is measured in the mathematically positive sense, proceeding from the tangent (TLV) to the mean line (BWL) in the inlet edge region. <EOS>