bids are invited for repair, maintenance, and installation of plant/ systems/equipments (version 2) - bsnl exge; electrical system or installation; service provider - supplying and fixing of following ms members for modification of existing ms structure work available at site for installing indoor / outdoor units including, cutting, welding, painting etc. asrequired. (design shall be got approved from engineer - in - charge before commencement of work) , suppling and laying of following copper piping from indoor unit and outdoor unit, on the existing gi tray i/c providing all the accessories such as collars, bends, cl s for copper piping i/c cutting, bending, brazing, painting the copper piping with red and yellow color with enamel paint and separte cl s etc as required. , pressure checking and leakage arresting of copper refrigerant pipe lines preliminarily by applying soap solution/foam on all the joints and checking, later filling the entire circuit with nitrogen gas to 300psi for 24hours, flushing the circuit and later vaccumizing using the vacuum pump and completely clearing the line from all dust, dirt, moisture etc., complete as required. , supplying and charging r-22 refrigerant gas in the existing refrigerant lines i/c transportation of gas cylinder to the site and filling the same in front of the engineer-in-charge / jto(e) etc., as required. , commissioning of 5tr after charging of gas after pressure testing i/c necessary presssure checking, proper operation of ac units etc. as required.