Abstract: Welding of heat exchange tube to tubesheet joint is a key process in the fabricating process of heat exchanger. The quality of strength welding joint should ensure both the pulling-out force and tightness of the joints. The connection quality impacts on the safety and stability operation of the heat exchanger directly. This paper analyzes and compares the requirements of relevant domestic and foreign standards for strength weld seam size. According to the results of the comparative study, it is recommended that the GB/T 151 standard should be unified with the foreign codes and standards when it is revised; the minimum leak path dimension a₀ should be adopted and the criteria for this weld seam size is suggested.

Key words: welding joint of heat exchange tube, strength welding, weld length, minimum leak path dimension, weld thickness