Method and device for checking the integrity of a flexible, nonporous bag with one or more bellows

A process of checking the integrity of a nonporous flexible bag with one or more gussets to detect leaks, the process comprising:

• in a preparation phase of the integrity checking:
• providing a bag with two facing large walls, and at least one lateral gusset with two facing small walls, at least one port on one of the large walls configured to be blocked or connected in a tight and stationary manner,
• providing a source of pressurized gas to be introduced into the bag via the port, providing means for measuring the pressure of the gas in the bag via the port,
• providing two fixed restraining plates spaced apart and facing one another, the fixed restraining plates being disposed such that the fixed restraining plates are not able to conceal a leak in the large walls of the bag placed against the restraining plates,
• providing one or more movable spacer strips configured to be placed between the restraining plates and inserted into the one or more gussets, and, after being inserted into the one or more gussets, being disposed to not block a leak in the small walls of one of the gussets placed against the one or more movable spacer strips,
• positioning the bag flat between two of the restraining plates,
• inserting at least one spacer strip between the two small walls of the one or more gussets in order to prevent the small walls from resting on one another, and
• connecting at least one port of the bag to the gas source and the pressure measurement means so as to be able to transmit the gas under pressure into the bag and to measure the gas pressure in the bag;
• in a testing phase of the integrity checking, transmitting the gas under pressure into the bag, expansion of the bag being limited when the large walls move against the restraining plates;
• and
• in a final stage of the integrity checking, comparing a pressure drop in the bag, using the pressure measurement means, to a predefined pressure drop threshold of another bag that is tight such that when the pressure drop in the bag is less than the predefined pressure drop threshold, the bag is indicated to have passed the integrity check, and when the pressure drop in the bag exceeds the threshold, the bag is indicated to not have passed the integrity check.