a flow rate (1.5 mL/min). d. Open the divert valve (counterclockwise turn of the black knob on the HPLC pump unit). Now the eluent bypass the column and detectors. Change the flow rate 5 mL/min and flush the system for 3 min. If you are using new solvents in the eluent bottles C and D, flush the system for 5 min. e.