tender for service contract for replace/repair of ventilation duct at track hopper with supply of materials at chp, stps-- 1 replace/repair of ventilation duct at th 2 fabrication and erection/replacement of damaged duct of ve&vs of track hopper with fabrication of new louvers /windows along with supply of 18 gauge new gi sheet, screw, asbestos rope etc. as per existing pattern. 3 fabrication,erection/replacement of duct supports of ve&vs of track hopper along with supply of materials like galvanized ms angle (25x25 /35 x 35 /40 x 40 angle of 3/4/5/6 thickness ),gi tie rod, hex bolt & nut (m8x25) etc. as per existing pattern and requirement.