The relationship between heat treatment and inspection
Thread Content
In some places, when heat treatment is required for head manufacturers, do local supervision and inspection authorities then require them to conduct inspections on those heads? I would like to ask everyone whether this statement is correct? In my understanding, heat treatment is only required by the local supervision agency for pressure vessels or their components (such as end caps, cylinders, etc.) that meet the requirements of TSG 21-2016 ； For pressure vessels or their components that do not meet the regulatory requirements and are subjected to heat treatment (such as heads or cylinders that are subjected only to external pressure, when the degree of cold forming deformation exceeds the values specified in GB/T 150.4-2011), no supervision by local inspection authorities is required ； I’m not sure if my understanding is correct; I hope the experts here can help reply. Thank you very much
Your understanding is basically correct. According to relevant Chinese regulations, during the manufacturing process of pressure vessels, heat treatment must be carried out in accordance with the requirements stipulated in the TSG 21-2016 Pressure Vessel Manufacturing License. If the head or other components have undergone heat treatment, the inspection department must conduct inspections on them to ensure their quality and safety. However, if these components do not require heat treatment, and no heat treatment is performed during the production process, then they do not need to be subject to supervision and inspection. .
Amendment No. 1 to the Fixed Volume Gauge explicitly requires that manufacturing supervision and inspection be carried out for the heat treatment of the head!
Containers that don’t fall into any category aren’t subject to regulation. Manufacturing them simply requires following the prescribed heat-treatment procedures. What does that have to do with regulatory authorities?
I understand that for end caps used in pressure vessels within the allowable range, if heat treatment is applied, supervision and inspection are required; otherwise, they are not necessary (for example, I understand that end caps of vessels under external pressure do not require supervision and inspection even if heat treatment is applied)
However, a head manufacturing factory in a certain area informed us that the local inspection authorities stated that, regardless of the intended use, as long as heat treatment has been applied, inspection is required. I think this is unreasonable. So please help analyze it as well. Am I correct in saying this? Thank you all for your prompt responses.
Supervision inspection is paid for; of course, supervision inspections are carried out on any type of end cap. The role of money
Containers that are not classified – what does that have to do with him?
Inspection is mandatory; it doesn’t matter whether money is involved or not – this is stipulated by the technical specifications. Technical specifications cannot take into account whether it will be used as a pressure vessel or not. Just like a gas storage tank is designed as a pressure vessel; after it leaves the factory it is not used as such, but you simply don’t need to obtain a permit for its use. By your logic that supervision is not needed, then there is nothing that requires supervision. It is even less possible to predict usage conditions for design, manufacturing, and inspection.
It is impossible to predict on what equipment end caps will be used. Unless the container manufacturer specifies that no supervision and inspection certificate is required when placing the order, for end caps that have undergone heat treatment, the end cap manufacturer will definitely require supervision and inspection.