タイトルまたは説明

Optimised performances and integration of the greatest number of functions are the objectives planned and achieved through the development of the HPV valves, a range of the latest generation of proportional directional valves that perform two simultaneous functions: directional control and flow control that is unaffected by load variations.
Their operation is based on the proportional hydraulic principle, i.e. keeping pressure loss constant through a variable section. The HPV spool can assume an infinite number of positions making the crossing areas infinitely variable, thus regulating the flow in relation to the pressure difference (Δp) throughout the entire operating range. By means of logical selection, an LS signal (feedback) is taken from the highest pressure ports and it’s sent to the flow-pressure regulator in the inlet section (if the circuit operates with a fixed displacement pump) or directly to the Load Sensing pump (for a closed centre circuit). As long as the circuit senses the Δp, the valve will maintain its proportionality properties.
Instead, if Δp tends to decrease, for example if actuator flow demand exceeds the overall pump flow (multiple simultaneous operations), the flow to the ports will be completely random, and in any case will tend to flow toward the actuators which will work at the lowest pressure values. The baric compensation provided by the two-way pressure compensators installed on each element, allows multiple operations to be performed at the same time without reciprocal effects. On the other hand, operating at the same time elements without compensators, the flows will vary in relation to the work pressure values.