What are the disadvantages of this approach?
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I would like to ask: what are the disadvantages of having two ring welds on a pipe that are too close to each other, and what consequences might arise? Thank you
Problems with the heat-affected zone. When a pipe is heated, does its internal structure change, causing it to be unable to withstand pressure?
Overlapping of the welding heat-affected zone can cause changes in the material properties.
The welds are too close together, and the heat-affected zones overlap, which prevents achieving peak quality.
It affects the material of the pipeline, altering its properties; if the welds are too close together and sufficient force is applied, cracks can easily occur
When welding the second layer, it is equivalent to performing a heat treatment on the first layer; as a result, the grain structure becomes coarse, the material is prone to cracking, and its corrosion resistance decreases. Such issues are specified in the standards as requiring corrective actions – it’s either a problem with the construction method or the design is flawed
This is the issue of overlap in the heat-affected zone. From an engineering design perspective, there are specified minimum distances between circumferential welds, and the design does not comply with these standards
You can also take a look at the medium; if it’s something like water, then it can be used as a makeshift solution – just accept any leaks that occur
The heat-affected zones are too close together and overlap. As a result, the microstructural properties of these two weld zones change; under welding conditions, coarse grains are formed, leading to increased brittleness and hardness, which alters the properties of the pipe material in those areas and increases the likelihood of issues such as cracking.