Order 1:

Connection sizes: G 3/8” BSP (D1 + D2 + U1 + U2) G 1/4” BSP (M1)

Order 2:

Connection sizes: G 1/2” BSP (D1 + D2 + U1 + U2) G 1/4” BSP (M1)

The purpose of lowering brake valves, also known as overcenter valves, is to prevent pulling loads on hydraulic cylinders or hydraulic motors from leading in an uncontrolled manner. The consumers are preloaded on the outlet side via the adjustable pressure valve. If necessary, this preload is released via an internal control bore, so that controlled movement is possible. The valves must always be set for the respective application.

If the pressure at D1 exceeds the preload pressure of the non-return valve, the flow is released from D1 to U1.

If the load pressure at U1 rises above the set value, the pressure relief valve opens and releases the flow from U1 to D1. If the load pressure at D2-U2 exceeds the set value, the pressure setting of the DBV is reduced proportionally to the specified load ratio until the pressure relief valve opens and releases the flow from U1 to D1. The DBV's spring chamber is relieved towards port D1. Due to the pressure-balanced pressure relief valve, the presetting of the valve is independent of the back pressure at D1. However, the control of the valve remains dependent on the pressure at D1. The open control line is hydraulically damped for greater stability at all flow rates and pressures. The setting value of the pressure cartridge should be at least 1.3 times the maximum expected load pressure

Scheme:

Additional information:

Controlled flow from “U1” to “D1”

Pressure setting must be at least 1.3 times higher than the load pressure.

Normally used when ports A+B are blocked in neutral position on the upstream directional control valve.

The set opening pressure is independent of the back pressure, while the opening pressure is still influenced by the back pressure.