The JPDF12 series reverse-acting hydraulic brake valve employs a direct-acting three-way pressure-reducing valve principle for return-flow braking systems. It functions as a service brake valve by utilizing spring- applied/hydraulically released brakes. “Reverse-acting” signifies that braking occurs by reducing the preset pressure, which maintains the brake in a fully released state. The preset pressure must be adjusted to a level higher than the pressure required for full brake release and maintained to prevent brake drag. Brake pressure is inversely proportional to the travel of the operating control element or the pedal travel angle, while the operating force is directly proportional to the travel of the actuator.

Technical Parameters

Hydraulic Schematic Diagram

Installation Schematic Diagram