Regarding the qualifications for boiler design

Individuals do not need to obtain proof; it’s not clear whether organizations do…

The unit does not require evidence-based design either, but the boiler’s design documents must pass evaluation. See TSG11-2020 Boiler Safety Technical Regulations

Firstly, boilers and pressure vessels were previously under the jurisdiction of the Ministry of Labor, and the designers in that field all belonged to the same specialty; nowadays, one of these fields relates to thermal energy while the other to chemical engineering – but the difference between them is not significant. Then, designing pressure vessels requires qualifications, and manufacturing them also requires qualifications. Boiler design does not require qualifications, while manufacturing does. Boiler drawings require approval and stamping by the special inspection agency, while pressure vessel drawings need to be stamped by the design manufacturer itself; this is why the design qualifications differ. This is also why you often see some boiler factories applying separately for the design and manufacturing qualifications for pressure vessels, as the personnel in the equipment factory are the same as those required for pressure vessels. It is quite interesting that manufacturing plants of pressure vessels rarely obtain the qualifications required for boiler manufacturing. Finally, a boiler actually consists of a pot and a furnace. A pot is a pressure vessel, while a furnace is a heating device. Those who can design boilers can generally also design Class I/II pressure vessels, whereas those who design pressure vessels usually do not design boilers. Because in addition to the calculations related to the strength, loads, and safe pressure release of pressure vessels, boilers also require thermal calculations, hydrodynamic calculations, smoke and air resistance calculations, as well as heat transfer calculations. Additionally, boilers also involve the calculation of many auxiliary equipment. In short, don’t always draw such a clear line between boilers and pressure vessels; they are like twins to each other. Their blood is compatible with each other. We’re all in the same field. They’re all the same kind of people: those who try to make a living through their skills, but end up as poor souls who can neither be well fed nor avoid starvation.

Boilers do not have separate design qualifications; when obtaining manufacturing qualifications, technical capabilities (personnel, product design documents for prototypes) are assessed.

Thank you to all the senior brothers who replied; I’ve learned a lot!