Main technical parameters to be achieved: the company plans to develop advanced ultrasonic testing, eddy current testing and through magnetic particle testing equipment, with the accuracy of 99.8% and the passing speed of 60-100m / min. The passing speed of magnetic powder and magnetic flux leakage testing equipment (abroad) reaches 60-90m / min, and the defects are automatically displayed. The welding rate of stainless steel finned tube plays a healthy role in heat transfer of convection section of furnace. High welding rate can give full play to the heat transfer function of finned tube on convection section tube, absorb heat brought by smoke to medium in tube, reduce flue gas temperature of furnace and reduce energy consumption, which is an effective means to save energy. Generally speaking, the single-stage cooling of muffler ZP100 can only reach - 40 ℃. In order to obtain a lower temperature, such as - 70 ℃, overlapping cooling is needed (R404A and R23 overlap). The refrigeration capacity of compressor can only be above - 40 ℃ (R404A).