INSTALLATION OF THE HYDRAULIC UNIT for the underwaterhatches type:001013 page 12

DISCUSSION OF THE HYDRAULICS. The motor provides the power for the fixed displacement axial piston pump Leduc. Both are connected by the means of an elastic coupling. The high oil pressure is provided through a high pressure flexible hose to the aluminium dispenser block. The return of oil towards the pump is prevented by the check valve C4V(Denison). The pressure control valve R1E02 (Denison) tops off the oil pressure till a maximum of 120 kg/cm². The manometer visualises the oilpressue;its service line may be cut by a needle valve. A hydropneumatic accumulator with a content of 1.5 liters, of which the nitrogen side is on 50 bars, assures a seamless operation in the low pressuer area. The Sofrance test connector enables measurements while operating. A needle valve, connected towards the oil tank, enables to depressurize the whole unit. Two pressure control switches assure the operating pressure area between 60 and 100 bar. Two PALL filters, one in the high pressure lines and one on the return lines guard oil quality. The cilinder is switched by means of the directional valve 4D01. (110V 60c/sec) The flow control valve DRV7 controls the amount of oil let though, and thus the cilinder speed. The cilinder in operation is never depressurized. The smaller chamber (inner surface of 6676mm²) is under pressure;this keeps the hatches closed. In operating the directional valve 4D01 the same pressure reaches the larger chamber of the cilinder.(9503mm²) The cilinder travels out and opens the hatch in a controlled manner under the influence of the same pressure on a differing surface. The cilinders pilot lines are connected on the flanges A1 & A2 of the dispenser block. The large flexible hose is a fill line for the cilinder.