Hydraulic Control

Control valves can be of either single- or multi-stage construction. Bernoulli forces limit the flow capacity of single stage valves to around 10 to 15 litres/min, most higher flow valves arc of two-stage construction, although three-stage valves are sometimes used for applications requiring very high now rates. Some pilot stages of two-stage valves can also [...]

A cross-sectional drawing of a proportional pressure relief valve is shown in Fig. 1. It is essentially a single variable orifice controlled by a proportional solenoid. A magnetic force proportional to the applied input current is generated and reacted by the pressure force. Typical steady-state performance curves are shown in Fig. 2. Since the valve [...]