Control valve of a compressed air system

A control valve (3) of a compressed air system of a vehicle, comprising:

• a housing forming a cylinder (25);
• a control piston (22) guided in an axially movable manner in the cylinder (25),
• two pressure chambers (32, 34) being separated from one another by the control piston (22),
• a sealing ring (37, 37′) arranged on the outer circumference of the control piston (22, 36) and sealingly engaging an inner wall of the cylinder,
• wherein the sealing ring (37, 37′) is a radial sealing ring having an axial length which substantially corresponds to the axial thickness of the control piston (22, 36), wherein the sealing ring (37, 37′) has two axial edges, each of which includes one respective radially obliquely outwardly directed sealing lip (39, 40) in contact with the inner wall (38) of the cylinder (25), and wherein a plurality of guide members (50, 51) distributed over the circumference of the sealing ring (37, 37′) are formed between the two sealing lips (39, 40) on the sealing ring (37, 37′).