Biennial Maintenance Contract Includes The Refilling, Repair, Painting, And General Maintenance Of Various Types Of Portable Fire Extinguishers. This Involves Periodic Cleaning, Checking, And Testing Of The Extinguishers Installed At 40 Metro Railway Stations On The Blue Line (Dakshineswar To Kavi Subash), Purple Line (Joka To Taratala), And Green Line I (Sector V To Sealdah). The Scope Further Extends To Electrical Substations, Av Complexes, S&Amp T Installations, Metro Rakes, Dg Rooms, Pump