Isobaric filling machines
Isobaric units are able to work with all products containing co2 in higher or lower quantities. Isobaric machines can also be used for products containing no co2, so-called still products.
Isobaric filling machines can be of the conventional mechanical type, or feature electro-pneumatic operation.
The mechanical version can be equipped with filling valves of different types depending on the type of product. The “s” valve, which is also the simplest, is used for products such as water or soft drinks and its only function is pressure equalization and final decompression. The ps valve pre-expels the air contained in the bottle before the pressure compensation by means of gas counter pressure. The more complicated but also more complete valves are the sl, psl, dps and dpsl where l stands for final levelling; these are particularly suitable for necks that are difficult to equalize with the isobaric machine, as in the case of the bordeaux bottle; d stands for double pre-expulsion where injection between the first and the second air pre-expulsion is through an external clean gas circuit. In the mechanical version, all these operations are controlled by cams.
The electro-pneumatic version differs substantially from the mechanical version because the different operations are part of a program and controlled by a plc with virtual cams.