Preventive measures for stress corrosion cracking of brazed plate heat exchangers　

Preventive measures for stress corrosion cracking of brazed plate heat exchangers:

Due to the incomplete understanding of the mechanism of stress corrosion cracking in metal materials and the numerous influencing factors, comprehensive preventive measures cannot be proposed at present. However, existing general measures have also achieved good results in production, mainly including:

(1) Reduce stress. When there is residual stress in the heat transfer element, it can be eliminated by annealing. Meanwhile, efforts should be made to eliminate or reduce tensile stress during the installation process as much as possible.

(2) Remove harmful media components

(3) Change materials. For example, although the uniform corrosion resistance of carbon steel is not as good as that of stainless steel, its stress corrosion resistance is better than that of stainless steel. Therefore, when corrosion is prone to occur, using carbon steel is safer and more economical.

Brazed plate heat exchanger is a compact and efficient heat exchanger with increasing applications, but it also exposes a significant drawback that cannot be repaired if leaks occur, especially internal leaks. An analysis was conducted on the failure reasons of a brazed plate heat exchanger in a foreign company. In order to fully utilize the performance characteristics of this heat exchanger, in addition to strictly controlling its manufacturing quality, effective prevention measures should also be taken from both design and installation aspects.