What factors should be considered in the structural design of the tower for high-pressure vessels?

The structure of high-pressure containers must ensure reliability in terms of strength and tightness of sealing. To guarantee this strength, so that the container does not suffer damage or excessive plastic deformation under specified pressures or other external loads, it is necessary to conduct a detailed stress analysis of the container’s structural elements. Comprehensive considerations including material selection and manufacturing inspections must also be taken into account, in order to determine appropriate shell structures and dimensions. To ensure a tight seal and prevent leaks during operation of the container, thereby avoiding fires or explosion accidents, it is necessary to carefully select the sealing structure based on principles such as simple design, reliable sealing, and ease of manufacturing, handling, and inspection. Since the wall thickness of a container increases as its diameter grows under certain pressure, this increase in diameter and wall thickness poses many difficulties in terms of material selection, sealing, manufacturing, inspection, transportation, and other aspects. Therefore, for the structure of general high-pressure vessels, provided that the operating conditions are met, when the volume is fixed, it is desirable to use a larger length-to-diameter ratio and to make effective use of the high-pressure space.

This post was last edited by dengzhijun on 2015-11-23 08:55. What factors should be considered in the structural design of the tower for high-pressure vessels? First of all, the container must meet the strength and stiffness requirements. Secondly, the rationality of the structure; here I am mainly referring to the location of the openings. They are installed on the head and the cylinder, and sometimes the amount of material required can differ significantly. Furthermore, at high pressures, multi-layer wrapping is often required; in such cases, if openings are made in the cylinder, it can lead to significant difficulties during welding. The multi-layer wrapping format involves multiple layers of wrapping for the cylinder section, while the end cap remains integral; this raises the issue of the overlap between the cylinder and the end cap. It is important to pay attention to the location where the edges are trimmed and the dimensions of the grooves, as different trimming locations can significantly affect the stress distribution at the overlap area. Then, there are the issues of sealing at the manhole and the design of the studs. For high-pressure applications, the most common types of seals I’ve seen are double-cone seals and those with ring-type connection surfaces (I can’t remember if they’re called octagonal gaskets). For double cones, the depth of the screw holes at the manhole ends must be strictly controlled, and there are also specific requirements for the design of the studs; the details depend on the relevant standards. Also, it is necessary to consider whether the studs can meet the strength requirements and fatigue criteria. Secondly, it relates to the selection of the connection flange and its sealing type; attention should be paid to the applicable ranges of various sealing surface types. Finally, regarding the treatment of weld positions on the containers, the welds in the main body should be polished to be level with the base material, while the joints at the pipe connections should have a smooth transition, meeting the specified requirements for smoothness. One more thing to add is regarding the form of takeover and hole reinforcement. Under normal circumstances, the nozzle can be thickened to meet the reinforcement requirements, but this thickening is not unlimited; the ratio of the nozzle thickness to the shell wall thickness must remain within a certain range. If thickening the structure is not sufficient to meet the reinforcement requirements, then reinforcing rings can be considered, or the use of fully forged components for reinforcement may be an option. As a last resort, thickening the wall thickness of the housing is the only alternative, but this approach comes with relatively high costs.