A method and apparatus for shaping plastic preforms into plastic containers, wherein at least three different pressure stages are applied to the plastic preforms in order to expand them, wherein the pressure stages are provided by at least three different compressed-air reservoirs, and wherein, additionally, the plastic preforms are stretched in their longitudinal direction by stretching rods, wherein compressed air is returned at least at times from the plastic containers to at least one compressed-air reservoir, and at least one value characteristic of the consumption of compressed air is detected.

Apparatus for forming plastic preforms into plastic containers, having a forming device which has a plurality of forming stations each having a stretching bar for stretching the plastic preform and an application device act upon the plastic container with a flowable medium. The forming device has at least four pressure reservoirs for the flowable medium, which each have predetermined pressures, and a valve block with at least five process valves. The application device is configured for producing a fluid connection between the valve block and a mouth region of the plastic preform in order to act upon the plastic preforms with the pressurised flowable medium, and the process valves are configured to act upon the plastic preforms with different pressures, wherein at least one process valve is configured for producing a connection between the plastic preform and an environment.

Disclosed is a method for operating a forming device for forming plastics material preforms into plastics material containers, wherein the forming device has a movable carrier on which a plurality of forming stations are arranged, wherein each of these forming stations forms plastics material preforms into the plastics material containers by applying a flowable and, in particular, gaseous medium in an operation mode, wherein in the operation mode at least two different pressure levels are applied to the plastics material preforms for the expansion thereof and at least two valves are used for this application, wherein at least one measured value is determined, at least at times, which is characteristic of a switching time and/or a switching time delay of at least one of the valves, wherein this measured value results from a pressure measured value.

A method for forming plastic preforms into containers, wherein a transport device transports the preforms along a transport path. The transport device has a rotatable transport carrier where forming stations are arranged for forming the preforms into containers. The forming stations each have devices which apply a flowable medium to the preforms, and the apparatus has three pressure reservoirs which store the flowable and gaseous medium to expand the preforms. The preforms are applied to a first operating mode with a first pressure level stored in the first pressure reservoir, and at least one second and one third pressure levels stored in the second and third pressure reservoirs. The second pressure level is higher than the first, and the third pressure level is higher than the second. The apparatus is operated in a second operating mode, which differs from the first mode by pressure level prevailing in the second pressure reservoir.