The DZL threaded line pipe shop-assembled steam boiler is the most advanced water-fire tube boiler in China, which is strong, highly effective, and with small volume , long working life. The ameliorated boiler uses the wing smoke flue, one-way threaded smoke pipe, arch tube sheet, smoke-gas segregation room, and several other advanced technologies so that the boiler bearing condition could be ameliorated, the circulating water flow speed could be improved and the safety coefficient could be enhanced. This series boiler is well designed , compactly made up, using either gas or water , shop assembled, mono layer, so that the civil engineering and the investment could be saved. This amelioration, which extends the boiler’s working life and is the national energy saving product, makes great contribution to the further development of boiler , it set the pace in china and fill up the national margin.