In the past 50 years, the basic function of the automatic control valve has not changed. Only the fixed basic performance has been increased, such as increasing the flow coefficient, reduce noise, reduce cavitation and improve the flow characteristics. However, the structural design characteristics change very slowly. Until the emergence of nuclear energy, valve manufacturers in the valve design had to consider the impact of such external forces as earthquakes. This paper discusses the improvement of control valves from the perspective of anti-seismic design; such as material selection, drive design and structure assembly, assembly of parts and so on. Nuclear power plant control valve must be able to withstand the impact of the earthquake. In fact, this is a prerequisite set by the United States federal regulatory code for a wide range of topics on the design, construction and operation of their nuclear power plants. 10CFFR50 is the "United States federal equipment manufacturing and license" on behalf of its Appendix A lists the "General Nuclear Power Plant Design Standards" (GDC). A paragraph in GDC-2 states: "The structures, installations and components of nuclear power plants must be designed to withstand the effects of natural phenomena such as earthquakes, tornadoes, Biao Feng ...". Other GDCs can also serve as a reference to indicate the necessary conditions for equipment to resist seismic and power constraints. These include GDC-1, I-4, I-14 and I-30. Although nominally, such generic standards that are not described in detail are virtually impossible to enforce. As the nuclear industry matures, the anti-seismic design and analysis of plant equipment will become clear, and all GDCs proposed by the industrial sector have a place in today's anti-seismic design control valve improvements. The Nuclear Regulatory Commission (NRC) has released the "Standard Test Plan" and "Standard Regulation Guidance." Various industrial organizations have also released a series of regulations and standards called the "NRC" required standard. Building designers and utilities are also beginning to issue relevant laws and regulations, and have clear requirements on the application of standard regulation guidance, standard inspection schemes and permits. At last. Control valve manufacturers to meet the industrial anti-seismic constraints and improve the product structure design. Prerequisites for Seismic Restriction (SQR) Initially, the control valve manuals usually contain few requirements related to anti-seismic conditions. They simply say something like "these valves can withstand natural phenomena such as earthquakes and tornadoes" or " Geographical implications are taken into account in design, "and there are usually no quantitative values ​​in these conditions. In contrast, today's instructions regarding the anti-seismic conditions section provide for acceptable limits and the rate of acceleration equipment must limit is very accurate. In very early factories, the anti-seismic design requirement was only that it was necessary when the equipment was placed in a very active seismic zone. The equipment and buildings in those plants are all designed according to the requirements of the Building Code (VBC) and use static analysis techniques. The anti-seismic design of 1965 formed a general specification of all nuclear power plants. There is enough evidence to show that the earthquake may have taken place anywhere, and earthquakes are possible both in areas with frequent earthquakes and in places that have historically occurred. Occurred in Massachusetts (1755); several major earthquakes in South Carolina (1876) in Missouri (1812) demonstrated that anti-seismic design should be considered in the design of nuclear power plants.
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