Abstract: A straight line disc valve for high pressure fluids is provided having a valve housing with an internal cylindrical chamber. A cylindrical rotor is aligned within the chamber with each end of the rotor being pivotable on a stationary disc within the housing. A passageway through the discs and rotor is alternately opened and closed by rotating the rotor. The rotor is actuated by hydraulic fluid acting on vanes radiating from the circumference of the rotor. Alternatively, the rotor is actuated by a gear positioned on the circumference of the rotor and rotatable within the housing. The first gear is driven by a second gear in communication with an outside power source.