Process sample and dilution systems automatically draw sample from a reactor or other source of sample and prepare drawn sample for subsequent injection to a chromatographic column or a detector. The process sample and dilution system has an external pump valve assembly in fluidic communication with a process sample manager. The external pump valve assembly includes an external sampling valve, an external process valve, external pump and a mixing tee. The external sampling valve can be configured to automatically acquire sample from a reactor or other source of sample. The external pump discharges wash from the external process valve whereby sample is discharged from the external sampling valve to the mixing tee for quenching and dilution and subsequent processing by the process sample manager.