The pressure control device ensures full flow output of the plunger pump below the control valve setting value. When the set value is reached, the outlet pressure of the plunger pump is stable within the set pressure range, and the output flow of the pump is reduced to meet the leakage and actuator demand flow, and the pressure is kept constant. The recommended pressure setting range is 0.5-35MPa, and the standard setting value is 35MPa.

The overflow valve is installed to realize the remote adjustment of the outlet pressure of the plunger pump. This pressure control device can ensure that the plunger pump is under the set value of the control valve when the full flow output is reached. When the set value is reached, the outlet pressure of the plunger pump is stable within the set pressure range, and the output flow of the pump is reduced to meet the leakage and actuator demand flow, and the pressure is kept constant. The recommended pressure setting range is 0.5-35MPa, and the standard setting value is 35MPa.

The load sensitive valve and the pressure cut-off valve are superimposed to realize that the load sensitive valve works when the pressure is lower than the set pressure of the pressure cut-off valve. At this time, the output flow rate is independent of the load. When the pressure rises to the set pressure of the pressure cut-off valve, the pump output flow rate is reduced to meet the leakage and the actuator demand flow rate, and the pressure is kept constant.

DF系列多路阀为片式结构多路阀，各换向联可以自由组合。该多路阀主要有进油体、换向联体、回油体三部分组成。DF系列换向联有多种滑阀机能，定位形式有钢球定位和弹簧复位两种，满足不同工况的需要。

The travel drive/winch balance valve is designed to reduce the risk of overspeed and cavitation of the axial piston motor in the open circuit. If the inlet pressure is reduced, the balance spool will throttle the oil flow back and brake the motor until the inlet pressure returns to approximately 2MPa.

This series of pumps combines the vane steering pump and the vacuum pump with a cross drive block to provide both vacuum to the engine braking system and power to the steering system.