本发明提供包含一个第一液压装置（M1）和第二液压装置（M2），所述两个液压单元（M1，M2）的装置由一个第一线（11）和第二线（12）为连接 向所述液压设备（M1，M2）中供应或排出油;增压泵（30），其布置在罐（R）和增压管线（10）之间，所述增压管线（10） 与所述第一和第二管线（11,12）中的至少一个连通并且能够通过所述增压泵（30）来供给所述第一和第二管线（11,12），其特征在于，所述管线包括低选择器 压力（50，72）连接所述增压泵（30）到所述第一管线（11）和第二线（12），该选择器（50，72）包括两个止回阀（51,52）背 （51a，52a）和座（51b，52b）的后面，每个都包括一个活门或密封件，该活门 所述密封元件通过杆（53）彼此分离，从而防止所述两个阀（51,52）同时关闭。

The invention provides a device comprising a first hydraulic device (M1) and a second hydraulic device (M2), the two hydraulic units (M1, M2) being connected by a first line (11) and a second line (12) for the admission or discharge of oil in said hydraulic apparatus (M1, M2), a booster pump (30) disposed between a reservoir (R) and a feeding line (10), the feeding line (10) being in communication with at least one of said first and second lines (11, 12) and which allow the feeding of said first and second lines (11, 12) by the booster pump (30), characterized in that it comprises a low selector pressure (50, 72) connecting the booster pump (30) to the first line (11) and second line (12) which selector (50, 72) comprises two nonreturn valves (51, 52) back- to-back each comprising a closure or sealing element (51a, 52a), and a seat (51b, 52b), the shutter s or sealing elements being separated from each other by a rod (53) preventing the two valves (51, 52) are closed simultaneously.