Why do ultra-high-pressure vessels need self-reinforcing treatment, and how is the circumferential strain on the inner wall of the cylinder controlled?

Self-reinforcing technology applies prestress to the inner wall of the cylinder, resulting in a more even stress distribution during operation and enhancing the elastic load-bearing capacity of the equipment. Pre-stress in the inner wall of the cylinder is typically obtained through heat-sheathing or overpressure (to cause partial yield of the inner wall). For the second part of the question, I don’t understand what the purpose of \"controlling the circumferential strain on the inner wall surface of the cylinder\" is Additionally, what standards are used to design ultra-high pressure vessels in China at present? The GB standard hasn’t been released yet, right?

In my opinion, due to the high pressure inherent in ultra-high pressure equipment, the residual stresses generated on the inner walls of the equipment during manufacturing remain within the device itself; when these stresses are combined with the external pressures applied (i.e., the pressures that arise after the container is put into use), it becomes easier for defects to grow. Such as welding cracks, undercutting, etc. Therefore, self-reinforcing treatment is required to ensure that residual stresses do not cause damage to the equipment itself. Regarding the control of the circumferential strain on the inner wall of the channel, I believe that by selecting an appropriate treatment method during the equipment’s self-reinforcement process – currently including mechanical extrusion, direct hydrostatic pressure methods, explosive methods, and solid self-reinforcement methods – the desired circumferential strain can be achieved.

GBT 34019-2017 for ultra-high pressure vessels – a standard already exists in China.