The STAG pressure/vacuum relief valve is used as protection against excessively high or low pressure conditions in containers and silos. If there is excessive overpressure in the container, the weight in the overpressure section is pushed upwards, air escapes, and the pressure drops. The escaping exhaust air is then directed via a connected pipeline to a desired location. This is important when the exhaust air, which may contain dust, cannot simply be released into the environment.

*If there is excessive vacuum in the container, the weight in the vacuum section is lifted upwards, air flows from the environment into the container, and the pressure rises.