Pneumatic pressure control valve for a brake control system of a rail vehicle, and pneumatic control valve for a brake control system of a rail vehicle

A pneumatic pressure-regulating valve for a brake control system of a rail vehicle, the pneumatic pressure-regulating valve comprising:

• a first pressure chamber, to which a brake pressure can be applied, and
• a second pressure chamber, to which a predetermined settable pressure can be applied,
• wherein the first pressure chamber and the second pressure chamber are sealed off with respect to one another by a pressure-equalizing piston, and
• wherein the pressure-equalizing piston is configured to open a fluidic connection from the first pressure chamber to a ventilation channel in response to the pressure action of the pressure on the pressure-equalizing piston in the first pressure chamber being greater than the pressure action of the pressure on the pressure-equalizing piston in the second pressure chamber,
• wherein the pressure-equalizing piston has a first piston portion, which faces toward the first pressure chamber, and a second piston portion, which faces toward the second pressure chamber, wherein a first end surface, which faces toward the first pressure chamber and to which the brake pressure is applied, of the first piston portion as a valve seat is smaller than a second end surface, which faces toward the second pressure chamber and to which the predetermined settable pressure is applied, of the second piston portion.