Pulse jet dust collector systems periodically inject short, powerful pulses of compressed air, in the direction opposite to the air flow into a filter bag or a row of filter bags. This air shot creates a sudden bag expansion that breaks the dust cake from the outer surface of the bags fabric. The dust is effectively removed by internal forces as the bag reaches maximum expansion and falls down into a hopper. Depending on the type of installation, typical pulse time is around 100 msec. while the interval between the pulses in each bag or row of bags is around 3 to 6 minutes. More and more the pulse sequence will depend on the differential pressure measurements over the filter bags