The scientific nature of the structural design of the bladder is also a key point of instant thermal technology. Instant water heaters are small and compact, and the power is very large, so the temperature change will be relatively large. If the structural design of the bladder is not scientific, it is also prone to problems such as water leakage, insulation degradation, performance degradation, and perforation of the heating tube. For example, if the heating tube is bent too much, the spacing of the tubes tends to be uneven, and even some places touch each other. In the course of use, the places where they touch each other are liable to be fouled more quickly and are less likely to be self-contained. Lost due to damage. Moreover, since the electric heating pipe is composed of an electric heating wire, an insulating heat-conducting layer and an outer pipe from the inside to the outside, multi-bending can cause cracks in the granular insulating heat-conducting layer at the bend, or the heating wire at the bend easily deviates from the electric heat pipe. Center, there are problems such as poor voltage tolerance. Therefore, the simpler the shape of the heating tube, the better.