构造为封闭的中心系统工作农业或建筑可用工作机的液压系统（1）的放大器阀（37）提供了一个或多个控制单元中的一个主负载信号线（17“）的基础上通过泵压力的装置（PP）生成的主负载压力信号 压力管线（10），放大的次级负载压力信号。 在这种情况下，通过主负载压力信号和放大器弹簧（44）在一方面增压阀（37）和，另一方面，通过被放大的二次负荷压力信号控制的控制阀（38），其中，在与所述压力线（10）的输入侧的控制阀（38）和上与输出侧 截止阀（39）已连接。 建立一个增压阀构造为封闭的中心系统，通过该液压消费者可以在没有所期望的工作速度的延迟来操作装置的工作的农业或建筑可用工作机的液压系统，应在凹部中形成为在锁定位置的第一工作位置（a）所述截止阀的 （39）关于该主负载信号线（17“），所述次级负载信号线（17），一个控制阀（38），导致信号线（45）和在罐（2）的返回（11）的致动，以接合在一起。

An amplifier valve (37) designed as a closed center system working hydraulic system (1) of an agricultural or construction usable working machine provides the basis of a one or more control units in a primary load signal line (17 ') generated primary load pressure signal by means of a pump pressure (p _p 10) a pressure line () an amplified secondary load pressure signal. In this case, the booster valve (37) on the one hand via the primary load pressure signal and an amplifier spring (44) and on the other hand, via the amplified secondary load pressure signal controllable control valve (38), wherein the control valve (38) on the input side with the pressure line (10) and on the output side with a shut-off valve (39) is connected. Establishing a booster valve for designed as a closed center system working hydraulic system of an agricultural or construction usable working machine by means of which the hydraulic consumers can be operated with no delay of the desired working speed, should in a recess formed as a locking position the first working position (a) of the shut-off valve (39) about this primary load signal line (17 '), the secondary load signal line (17), a to an actuation of the control valve (38) leading signal line (45) and a return (11) in a tank (2) to be joined together.