Dust extraction bags need to be checked and replaced regularly. There is a common misconception that a dust extraction bag does not need to be changed until the volume of the bag is full. This is not correct; the capacity of a dust bag is roughly 1/3 of its total volume. This is due to the compression effect of settled dust.
If you fill bags beyond this level you will run the risk of rupturing the bag which wall cause dust to clog the filter and get into the internal components of the dust extractor. If this occurs, at a minimum you will have a very messy clean up job and will likely need to replace the filter, and at worst damage the electrical components of the dust extractor to the point of rendering it inoperable. You will not be covered under warranty if the cause of damage is the result of a ruptured bag from over filling.
Below is an example of what a ruptured bag will do to the internals of your dust extractor. The filter on the left is new, the filter on the right is from a dust extractor with a ruptured bag.
All top outlet 20L and 40L pressure pots now incorporate a full stainless steel fluid trail. This ensures they will not react with corrosive fluids and will significantly increase the operational life of the system.