bids are invited for filter media removal of irp - lifting of filter media from package type irp filter chamber asper specification and the direction of the engineer-in-charge. , supply of polyprophylene hexagonal nut - providing and fitting fixing polyprophylene double hexagonal nut strainer(threaded type)inside the irp vessel as directed by the engineer-in-charge. , supply of irp filter gravel - providing and placing filter gravel having effective size of3.00 mm to 25 mm & uniformity co-efficient of not more than1.70 and or less than 1.30 obtained from barakar river, westbengal as per specification and the direction of the engineer -in-charge. , supply of irp filter sand - providing and placing rapid gravity filter sand having effectivesize of 0.50 mm to 1.00 mm & uniformity co-efficient of notmore than 1.70 and or less than 1.30 obtained from barakarriver west bengal as per specification and the direction of theengineer - in - charge. , supply of irp anthracite coal - providing and placing of anthracite coal ( 3 mm to 6 mm) ofsp gr. 1.4 in irp as per specification & direction of theengineer-in-charge. , supply of irp mno2 - supplying cleaning and placing of mno2(size 20 mm to 40 mm) inside the oxidation chamber between two plate including removing exixting old mn02 from the chamber disposal within 50 m lead complete as per specification and direction of engineer-in-charge , nut bolt - supplying and fitting fixing 0f 5/8x2 inch nut bolts of approved quality as per direction of engineer-in-charge , supply of gi bend - providing and fixing g.i. bend /elbow in the pipe line includingtesting of joints complete as per cpwd specification anddirection of the engineer - in - charge.xi. 150 mm dia , synthetic enamel paint - 13.52 painting with synthetic enamel paint ( one or morecoats ) of required colour of approved brand andmanufacture on old work to give an even shadeincluding preparation of surface as required completeas per direction of the engineer in charge , cidf b