a system for distributing a piped fluid uses a plurality of valves arranged along a fluid conduit . the valves are successively opened for a selected period of time by a plug element inserted in the conduit and carried by the fluid . the plug element engages the valves and opens each valve in response to fluid pressure . in a preferred embodiment , the plug element upon completion of a circuit through the conduit automatically reverses the direction of fluid flow . there is also disclosed a sprinkler head for use in connection with the distribution system .