bids are invited for custom bid for services - dhds unit structural replacement,10 main load bearning column/beam replace 20 fabrication. & erection of structure 30 paint: zinc phosphate primer coating 40 paint: inorganic zinc silicate primer 50 hiring of mobile crane - 16t capacity 60 hiring of tractor trailer 70 copper slag/grit blasting - sa 2-1/2 80 overlay patch - cs - 6 to 12mm thickness 90 system scaffolding - upto 6 mtrs height 100 system scaffolding - 6 to 12 mtrs height 110 system scaffolding - above 12mtrs height 120 dismantling of old structure & piping 130 non-pressurized piping welding 140 cs welding crew at unit/site 150 supply of chipper/mason 160 hiring of mini-tractor trailer 170 replacement of gratings - with welding 180 hot work area preparation - mud packing