The most notable feature of plate heat exchangers which is different from other devices is its non-standardization. The molds of each equipment factory are self-developed and each has its own characteristics. Therefore,the plate heat exchanger area of the same heat exchange system will change due to different equipment manufacturers. This designer reminds the design specification, otherwise the owner replaces the equipment manufacturer under the premise that the plate heat exchanger area is unchanged. There will be unintended consequences.