bids are invited for repair, maintenance, and installation of plant/ systems/equipments (version 2) - manufacturing unit; e3717 biennial rate contract for opening and boxing up of manhole covers (both bolted and welded) for vessels; as per scope of work - rectangular 1500x 500x 12 mm thk (cs) plate , rectangular 500x 500x 8/10/12mm thk cs duct , rectangular 500x 500x 8/10 mm thk ss duct , 24 circular 12 mm thk (cs) , replacement of sulphur pump ( burner/ transfer pumps) , coupling inspection and replacement , replacement of melting tank agitator , replacement of pump tank agitator , melting tank agitator gear box replacement , dirty tank agitator gear box replacement , melting tank agitator coupling inspection and pin/bush replacement , dirty tank agitator coupling inspection and pin/bush replacement , replacement of steam coil in melting tank , replacement of steam coil in dirty tank , replacement of steam coil in clean tank , hydro testing of steam coil in melting tank , hydro testing of steam coil in dirty tank , hydro testing of steam coil in clean tank , removal, overhauling and replacement of the cooling water pump , coupling /decoupling of cw pump , replacement of vertical iat pump , coupling inspection and replacement of iat pump , replacement of vertical pit recovery pump , coupling replacement of pit recovery pump