Western Coalfields Limited Tender

Supply and recharging the filter tanks of rapid gravity filters with approved quality filter media given below A) silica sand filter media i) grade 16/30 i.e 0.5mm to 1.10 mm layer thicness 200mm ii) Grade 12/16 i.e. 0.85mm to 1.70 mm layer thickness 200mm iii) 10/12 i.e. 1.00mm to 2.00mm layer thickness 200mm specification/ characteristics i) uniformity coeffieceint not less than 1.40 ii) specific gravity 2.65 iii) bulk density 1600 kg/ cu.m. iv) silica content 97.00 % (v) Hardness 7 Moh. 9vi) acid solubility (24 hrs in 20% HLC) below 1% vii) colour tan to off white B) support gravel grade 1/10" to 1/4" i.e. 4mm to 6mm layer thickness 100mm (ii) grade 1/4" to 1/2" i.e. 6mm to 12 mm layer thickness 100mm iii) Grade 1/2" to 1" i.e. 12mm to 25mm layer thickness 100mm total layer thickness 300mm specification/ characteristics i) specific gravity 2.65 ii) bulk dencity 1850 kg/m iii)shape rounded iv) hardness 7 moh v) silica content 95% vi) ACID solubility (24 hrs in 20% HCL ) below 2%

Over hauling and cleaning of filter beds incliuding lateral pipe, removing of old filter media and cleaning of fresh media.

Painting with black anti-corrosive bitumastic paint of approved brand and manufacture to give an even shade : Two or more coats on new work