A pressure compensation and mixing device includes: a mixing unit configured to mix a fluid guided in the mixing unit; and a pressure compensation unit configured to restrict pressure rising in the fluid. The mixing and pressure compensation units are integrated in a container unit. The mixing unit has a mixing volume. The pressure compensation unit has a pressure compensation volume. The mixing and pressure compensation volumes adjoin each other and are separated from each other at least partially by a common separating wall. The pressure compensation unit is arranged inside the mixing unit. The mixing unit includes: an inlet tangentially arranged on the mixing volume such that a fluid let in through the inlet flows in tangentially into the mixing volume; and an outlet axially arranged on the mixing volume such that a fluid let out through the outlet flows out of the mixing volume axially.