When can tack welds used in the assembly of vertical joints in tank shells remain in place during dismantling and reconstruction?

When can tack welds used in the assembly of vertical joints in tank shells remain in place during dismantling and reconstruction?

• A. They are properly cleaned of all weld slag
• B. They are sound
• C. Liquid penetrant or magnetic particle examination is performed
• D. They shall not remain

Answer: (D)

Tack welds are temporary welds used during the assembly of vertical joints in tank shells to hold components in place until the final welds are made. The purpose of these tack welds is specifically to aid in the positioning of pieces before the permanent welding is completed. According to API 653 guidelines, tack welds shall not remain in place during dismantling and reconstruction because they are not intended to be part of the final structural integrity of the tank. Tack welds are considered non-permanent and may not have the same strength or durability as the final welds that are designed to handle the operational loads and stresses on the tank. Once the final welds are made, maintaining tack welds can create issues such as weld discontinuities or weaken the overall structure, which could affect the tank’s integrity. Therefore, the standard practice is to remove any tack welds before dismantling or reconstructing the tank, ensuring that any final connections are solidified without the presence of temporary assemblies, thereby adhering to safety and operational standards.

Tack welds are temporary welds used during the assembly of vertical joints in tank shells to hold components in place until the final welds are made. The purpose of these tack welds is specifically to aid in the positioning of pieces before the permanent welding is completed.

According to API 653 guidelines, tack welds shall not remain in place during dismantling and reconstruction because they are not intended to be part of the final structural integrity of the tank. Tack welds are considered non-permanent and may not have the same strength or durability as the final welds that are designed to handle the operational loads and stresses on the tank.

Once the final welds are made, maintaining tack welds can create issues such as weld discontinuities or weaken the overall structure, which could affect the tank’s integrity. Therefore, the standard practice is to remove any tack welds before dismantling or reconstructing the tank, ensuring that any final connections are solidified without the presence of temporary assemblies, thereby adhering to safety and operational standards.