inlet process piping into the valve assembly 30 via port 50 into chamber 60 across valve 70 into chamber 62 and out port 52 into a chromatography column product returns from the chromatography column entering the valve assembly 30 through port 56 into chamber 66 across valve 74 into chamber 64 and out to the outlet process piping through port 54 as in the case where the fluid is flowing in a forward direction chambers 60 62 64 and 66 are common to two valves respectively this time 70 and 74 and the fluid being piped through each port 50 52 54 56 will flush and sweep through the chamber preventing stagnation and the opportunity for contaminants or particulates to accumulate and or growth of microorganisms to develop the chromatography column may be bypassed altogether as is depicted in fig4 c according to this process flow liquid enters the valve assembly 30 through port 50 and passes into chamber 60 the fluid then crosses valve 78 and passes into chamber 64 from chamber 64 the fluid exits the valve assembly 30 through port 54 during the column bypassing process valves 70 72 74 and 76 remain closed and fluid remaining in chambers 62 and 66 as well as in the column remains undisturbed in the process the valve assembly 30 described herein is simple and easy to use and represents an improvement over prior art diverter valve assemblies the device is machined out of one block of material and all flow compartments are shared and fully flushed when a flow through valve is opened thereby eliminating dead legs.