Barmac 6900 Duopactor VSI for sale, Barmac 6900 Duopactor VSI, Year 1990. VSI Imapact crusher comes on Sub Stand, there is no Frame, Motor or Lube Station but all can be sourced at additional cost. This Barmac 6900 Duopactor is a Secondary crusher. Max feed size 37MM, Rotor RPM range 1500-2500 RPM, Max throughput 105-150TPH.