Arrangement of things side by side whereby both the inputs and outputs for elements are connected to each other. When hydraulic resistances are arranged in a parallel circuit, the flow rate in the individual branches is divided up in inverse proportion to the resistance (Figure P 1).
- The arrangement of devices in a parallel circuit, also referred to as redundancy, improves reliability but involves higher costs.
- When sub-circuits are arranged in a parallel circuit, several loads (cylinders, motors) are supplied by a single drive (pump) (single circuit system). When cylinders are arranged in a parallel circuit, it is important to ensure the element with the lowest resistance (load, friction) to overcome starts the movement (Figure P 2). The next actuator only follows suit when the pressure at this point increases.

Figure P 1: Resistances connected in parallel

Figure P 2: Parallel circuit containing three cylinders