Milking installation, milking equipment and teat cup liner, and associated operating method

A milking installation comprising at least one milking cluster with four teat cups, wherein each teat cup comprises a cup housing and, accommodated in the cup housing, a teat cup liner with a top region and a suction region, wherein a connection for a milk tube is arranged at the cup bottom or at the end of the suction region of the teat cup liner, and a connection for a pulsator line is preferably arranged on a wall or bottom portion of the cup housing, and a mouth portion of a sterile air pressure line is arranged in the top region of the teat cup liner, through which pressure line sterile air is introduced at a volumetric flow rate greater than a fluid aspiration volumetric flow rate at the milk tube, such that a sterile air blanket is established in the top region of the teat cup liner, wherein at least one central sterile air pressure line with at least one sterile air filter installation is included, by which each sterile air pressure line of the milking cluster is centrally supplied with sterile air, such that a sterile air volumetric flow rate is established in each sterile air pressure line which is higher than a fluid aspiration volumetric flow rate in each milk tube, whereby a sterile air blanket is established in each teat cup.