ที่มา:American Society of Mechanical Engineers. (2019). ASME BPVC Section IX, qualification standard for welding, brazing, and fusing procedures; welders; brazers; and welding, brazing, and fusing operators. New York: The American Society of Mechanical Engineers.
ที่มา:American Society of Mechanical Engineers. (2019). ASME BPVC Section IX, qualification standard for welding, brazing, and fusing procedures; welders; brazers; and welding, brazing, and fusing operators. New York: The American Society of Mechanical Engineers.
ที่มา:American Society of Mechanical Engineers. (2019). ASME BPVC Section IX, qualification standard for welding, brazing, and fusing procedures; welders; brazers; and welding, brazing, and fusing operators. New York: The American Society of Mechanical Engineers.