Basic design for a hydraulic drive in which the pump draws in the hydraulic fluid from a storage tank, the surface of which is open to atmospheric pressure. The oil is conveyed to the consumer via directional valves and once the work is performed, is fed back to the tank. It is not possible to reverse the direction in terms of pump delivery. Excessive negative pressure in the suction line should be avoided.
A reversal of direction for the output element (cylinder, motor) is achieved via a directional valve.
Alternative: closed circuit.
Typical design for a hydraulic system with an open circuit