... liquid bypass occurring due to needle holes.Type Pocket Filter Usage Liquid Filter Certificate ISO Liquid filter bag 1. (micron): 1, 5, 10, ... 150, 200 2. International standard filter bag: ES-1, ES-2, ES-3, ES-4 Liquid filter bag Filter bag filter ability(micron): 1, 5, 10 ... 75, 100, 150, 200 International standard filter bag parameter: ES-1, ES-2, ES-3, ES-4 PPS thermally welded pocket filter bags