Post-weld stress relief heat treatment

Is this equipment classified as such? If it is, then according to Article 73, \"High-pressure vessels, medium-pressure reaction vessels and storage vessels, horizontal storage tanks for storing mixed liquefied petroleum gas, and mobile pressure vessels shall undergo overall heat treatment inside a furnace.\" Other pressure vessels shall undergo overall heat treatment. For large pressure vessels, segmented heat treatment can be employed... According to the regulations, except for welded joints that have been repaired and for which partial heat treatment is permitted, heat treatment is applied to the entire vessel; therefore, according to these regulations, your approach is at least not in compliance with the standards. Why do you want to do this? Is it because the vessel is too large to be treated as a whole? There is a type of internal combustion-based heat treatment that might be able to solve this problem.

Local heat treatment is certainly possible, but what the original poster said – \"using electric heaters (coiling wires, tracks) to cover all the welds and then wrapping the container tightly with insulating material\" – is intended to address the issue of overall heat treatment after welding.

Wrap the entire device with an electric heater (coiled wire or belt), and then cover the container tightly with insulating material

Personally, I think it’s fine as long as it’s handled well

"An electric heater (coiled strip, crawler) is used to wrap around all the welds, after which the container is tightly covered with insulating material; this method can also be considered a form of localized heating treatment.

This should be called local heat treatment.

In my opinion, insulation should be provided on both sides of the container walls, and the temperature on the inner wall should also be monitored using thermocouples; otherwise, it will be difficult to control the temperature inside the walls, and the required temperature for heat treatment may not be achieved.

If heat treatment can be carried out in this way, it will solve a practical problem for pressure vessel manufacturers like ours that do not have heat treatment furnaces. Another advantage is that the heat treatment equipment can be shared with pressure pipelines.

Thank you all for the insightful discussions; I have learned a great deal from them. :handshake :handshake

Overall heat treatment generally involves furnace-based overall heat treatment; using local heat treatment as a substitute is rather hasty, as it’s difficult to ensure quality in such cases.