annual maintenance contract of solar water heating system , maintainance of repair of solar water heting systems , supplying and erecting hot water storage tank 1000 ltr. capacity with stand(mnre/meda) , supplying and erecting hot water storage tank 500 ltr. capacity with stand (mnre/meda) , supplying and erecting 16/20 (idod) mm polyethylene composite pipe , supplying and erecting 20/25 mm (idod) polyethylene composite pipe , supplying and erecting g.i pipe 20 mm dia b class with resin bonded flap rock wool/glass wool insulation, with necessary material , supplying and erecting g.i pipe 25 mm dia b class with resin bonded flap rock wool/glass wool insulation, with necessary material , supplying and erecting g.i.pipe 15 mm dia. ‘b’ class , supplying and erecting isi mark g.i.pipe 20 mm dia.‘b’ class , supplying and erecting isi mark g.i.pipe 25 mm. dia. ‘b’ class , supplying and erecting iron work for panel board or other purposes , supplying and erecting chromium plated heavy duty brass stop cock for inlet pipe of water heater (15/20 mm. ). , supplying & erecting solenoid valve size 1 material ss 304 , replacement of old fpc solar water heating panels by new etc solar manifold panels. solar etc manifold (adequate for capacity 500 lpd) should have ss inner with 50 nos. etc tube of size 58mm x 1800mm triple layer. tube holders of manifold should be in metal and mounting stand should have adequate strength.(old panels to be submitted at estate section ) , replacement of old fpc solar water heating panels by new isi marked fpc solar panels. solar fpc panel (adequate for capacity 125 lpd) should have cu-cu fin and tube assembly with ultrasonic welding. fpc panel should be supplied with mounting stand and installation to existing system tanks. (old panels to be submitted at estate section ) , supplying & erecting etc tube (mnre/meda) (58x1800mm) , supplying and erecting quartz electronic time switch having 24 hour dial to work on 250v 50 cycle a.c. having built in rechargeable nickel cadmium b