The invention relates to a ventilation flow rate regulator (1) for a pressurized vehicle tank (4), which comprises a plunger (10) adapted to be mounted in a ventilation line (7). The plunger (10) has at least one peripheral orifice (111) and at least one non-central internal orifice (112) which is closer to an axis of symmetry (A) of the plunger (10 than the peripheral orifice (111). The non-central internal orifice (112) has a section perpendicular to the axis of symmetry (A) which is smaller than any section of the peripheral orifice (111) perpendicular to the axis of symmetry (A).