本文首先对纯水传动介质的物理化学性质做了全面分析。理论推导出对于相同管径、相同流速的管路系统，在层流状态下，纯水在管路中的单位长度压力损失与矿物油在管路中的压力损失比值，分析了纯水质量控制的重要性，并阐述了磁化、杀菌和精细过滤等提高纯水质量控制的方法。 对纯水溢流阀的设计理论和方法进行了研究。以油压溢流阀的设计方法为基础，论述了纯水溢流阀的设计理论和方法与传统油压阀的异同，阐述了纯水溢流阀设计的关键技术，提出了解决措施。对其结构做了分析，对主要尺寸进行了设计。 分析了纯水溢流阀的结构性能。建立了纯水溢流阀的数学模型，对其静态性能和动态性能做了研究。利用所建立的数学模型对纯水溢流阀的静态动态特性作了仿真分析，得出了影响阀体稳定性的主要因素。

Firstly in this essay, physical and chemical properties of the pure-water transmission medium are analyzed comprehensively. Ratio of unit pressure loss of pure-water and mineral oil flowing in pipelines with same diameter and flowing velocity in laminar state is deduced in theory. The importance of pure-water quality control is analyzed, and the methods (magnetizing, bacteria-killing, fine filtering)of quality control are expounded. Design theory and methods of pure-water relief valve are studied. This essay discusses the difference and sameness which exist in design theory and methods of pure-water relief valve and traditional oil relief valve based on design methods of oil relief valve, key technologies of the pure-water relief valve are expounded and solutions are proposed, too. Its structure is analyzed and its main sizes are designed and design theory and methods of pure-water relief valve are studied. The structural performance of pure-water relief valve are analyzed. Mathematical model of pure-water relief valve is built, its static and dynamic performance are studied. Static and dynamic performance of pure-water relief valve is simulated using mathematical model which is built in this essay, the main factors which affects the stability of valve’ body are obtained.