load chamber 22 and pressure sensing passage 39 to load chamber 23 pressure in load chamber 22 transmitted through pressure sensing passage 35 will activate through line 37 the differential pressure compensator 13 in the manner as previously described simultaneously pressure signal from load chamber 23 will be supplied through sensing passage 39 and will be transmitted to space 41 through passage 40 assume that the positive load generates a positive sustaining pressure in load chamber 22 then the load chamber 23 will be at zero pressure and therefore zero pressure signal is transmitted through pressure sensing passage 39 to space 41 further movement of valve spool 17 from left to right will connect load chamber 22 to inlet chamber 21 and load chamber 23 to outlet chamber 25 since in the position as shown control spool 29 connects outlet chamber 25 with exhaust chamber 30 the fluid flows from inlet chamber 21 to load chamber 22 and through line 22a to fluid motor 11 and out of fluid motor 11 through line 23a to load chamber 23 and outlet chamber 25 which through passage 26 outlet chamber 24 passage 27 and control spool 29 is connected to exhaust chamber 30 which in turn through line 34 is connected to reservoir 33 for the positive load condition as just described the speed of the fluid motor is fully controlled by the area of the orifice between the inlet chamber.