NONWOVEN DISC FILTER BAGS FOR GF- 1/ 2 FILTER AS PER, DRG. NO. NALCO/ P & D/ M- 190, Q3, NON- WOVEN DISC, FILTER BAG FOR DORR- OLIVER FILTER AS PER DRAWING, NALCO/ ORN/ 3027, NON WOVEN DISC FILTER BAGS, FOR BOKELA FILTERS AS PER DRAWING NO., NALCO/ OPRN/ 3112, NONWOVEN DISC FILTER BAG GF-, 4 FILTER AS PER DRAWING NO- NALCO/ OPRN/ 5739