The boiler headers have water wall header, superheater header, economizer header and so on, it acts as collection, mixture, re-distributing working medium. From the structure, it can be classified as the end cover type (end closure) and necking down type. Steam header is the main equipment of boiler for allocating the steam to the all pipe. Steam header is a Pressure Vessel ;the main function is to allocate steam.So steam header has many valves to connect the boiler main steam valve and steam distribution valve,and make the steam into anywhere. 1. Strength calculation report with applied materials information; 2. 100%NDT(non-destructive inspection) report of steel plate, tube and welding rod; 3. 100%X-ray inspection report (welding seam): to ensure the quality of the entire boiler; 4. Hydraulic test report: ensure the standard working pressure and safety