Work dealing with the development of a repetitively pulsed, high average power DF chemical laser is discussed. Primary emphasis is on demonstration of a scalable fuel/diluent feed system which allows fuel combustion to be extinguished between pulses. A valving concept is described where fluorine and diluent flow through the cavity on a steady-state basis and deuterium flow occurs through a valve which opens only when the lasing mixture is filling the cavity. A flow device utilizing this valving concept has been built and tested. Flame-out was achieved at 50 pps using fuel mixtures consisting of 70% He/20% F2 /8% D2 /1-2% 02 with fuel-to-purge ratios of 1:1.