Pipe line types,valves,laying,erection,quality control,planning,utilisation,hydro test,commisining,uses of valves like butter fly valve,scover valve,non return valve,sluice valve, types of joints,pressure ranges for hdpe pipe jointing, cooling time of hdpe pipe jiont,melting point of hdpe pipe line, in di pipe line flow direction, hydrostatic test formula, daily activity of site, planning of future work, boq planning, specials of hdpe and di pipe line, valve fixing positions .