Abstract: A system which has a body (20) with internal pasageways and a hollow connecting sleeve (24) attached thereto. A hollow union (32) is rotatably retained on the sleeve (24) and a gasket (30) provides a seal therebetween. A pair of adjustable arm stops (34) attach to the union (32) confining the rotational movement. A nozzle (36) is joined to the body (20) with an arm (42) distending parallel with the nozzle (36) and a pivotal member (44) extends upwardly therefrom. A plate (46) is swivelly mounted on the member (44) with means to limit the pivotal movement connected to the arm (42). The fluid from the nozzle (36) impinges on the plate producing unequal torque on opposed sides of the plate (46) as it pivots upon the member (44) causing the entire arm (42) to axially advance. In the reversing embodiment a torque differential and flow impingement upon the stop (34) combine energy functions and reversers.