BHF Series High Flow Pleated Filter Cartridges Series high flow pleated filter cartridges are made from depth fine PP or GF non-woven fabrics.The filter has a big diameter of 6 inch/152mm and no inner core, single open.The inside to outside flow pattern ensure that all the particles will be intercepted at the inside of the filter.The long service life and high flow rate result in low investment and less manpower in many applications.