A reversible hydraulic pressure converter (1) employing tubular valves, comprising:
- a medium-pressure stage (44) consisting of a medium-pressure cylinder (2) each of the two ends of which is closed by a medium-pressure head (4) and in which can move in translation in a fluid-tight manner a double-acting medium-pressure piston (3) that has a pressure face (5) facing each medium-pressure head (4) while said medium-pressure cylinder (2), said heads (4) and said pressure faces (5) form two medium-pressure chambers (6) axially positioned on respective opposite sides of the double-acting medium-pressure piston (3);
- at least one high-pressure stage (45) consisting of a piston connecting rod (7) for each pressure face (5), said rod (7) being fastened to the double-acting medium-pressure piston (3) and to a high-pressure piston (8), said rod (7) passing in a fluid-tight manner through the medium-pressure head (4) so as to extend into a high-pressure cylinder (9) the diameter of which is smaller than that of the medium-pressure cylinder (2), while the high-pressure piston (8) can move in translation in a fluid-tight manner in the high-pressure cylinder (9), the high-pressure cylinder (9) being closed by a high-pressure head (10) so as to constitute with said high-pressure piston (8) a high-pressure chamber (11);
- at least one tubular valve (12) for each medium-pressure chamber (6) adapted to place the medium-pressure chamber (6) in communication with a medium-pressure inlet-/outlet circuit (15), said valve (12) cooperating with an independent valve actuator (13);
- at least one tubular valve (12) for each high-pressure chamber (11) adapted to place the high-pressure chamber (11) in communication with a high-pressure inlet-outlet circuit (16), said valve (12) being adapted to be actuated to be opened or closed by an independent valve actuator (13);
- at least one piston position sensor (14) that can transmit to a control computer (19) of the converter the position of the double-acting medium-pressure piston (3) or the position of any of the high-pressure pistons (8),
- the tubular valve (12) includes at least one rectilinear tube (20) hollowed out in the axial direction to form a balancing passage (32), said at least one rectilinear tube (20) being accommodated with a small clearance in a tube cylinder (24) to constitutes a seal, and said at least one rectilinear tube (20) being movable in longitudinal translation in said tube cylinder (24), the tube cylinder (24) being mounted on or disposed in a valve casing (21) inside which is provided an annular internal chamber (22) into which discharges an annular chamber inlet-outlet orifice (23) that communicates with an annular chamber inlet-outlet passage (37), said tube cylinder (24) discharging into said annular internal chamber (22), the annular internal chamber (22) including a closure seat (27) opposite and coaxial with said tube cylinder (24), while the at least one rectilinear tube (20) has on the one hand a first end (25) located in the annular internal chamber (22) and terminated by a contact flange (34) that can come into annular contact with the closure seat (27) externally of the balancing passage (32) so as to constitute a seal with said seat (27) and on the other hand a second end (26) that discharges into a balancing chamber (31) and is mechanically connected to the valve actuator (13), the balancing passage (32) establishing communication between the closure seat (27) and the balancing chamber (31).