Photo of gas-liquid linkage actuator for main steam isolation valve and main feedwater isolation valve
Main steam isolation valve and main feedwater isolation valve pneumatic hydraulic actuator
2025-06-14
On November 16, 2022, the prototype appraisal organized by the China Machinery Industry Federation and the China General Machinery Industry Association was passed. The appraisal opinion was that the developed main steam isolation valve and main feedwater isolation valve gas-liquid linkage actuator filled the domestic gap, had independent intellectual property rights, and all performance indicators reached the advanced level of international similar products. Some indicators were better than foreign products, reaching the international leading level, and could be promoted and applied in Hualong One and other nuclear power units.
Technical Parameters
Product Details
Scope of application: Pneumatic hydraulic actuators have the characteristics of high reliability, fast closing action, and high thrust, and are widely used in the main steam isolation valve and main feedwater isolation valve of pressurized water reactor nuclear power plants. They are key valves in pressurized water reactor nuclear power plants. In the event of a unit accident, the valve needs to be quickly isolated (with a closing time of less than or equal to 5 seconds), cutting off the flow of main steam and main feedwater to ensure the safety of the unit.
Application status of achievements: Dalian Dagao signed a procurement contract for LOT190D main steam isolation valve and full load isolation valve of Units 5 and 6 of the Lufeng project with China General Nuclear Power Engineering Co., Ltd. in 2021, based on the pneumatic hydraulic actuator of the main steam isolation valve and main feedwater isolation valve. It is expected to complete the supply this year.
In 2023, a procurement contract was signed with China General Nuclear Power Engineering Co., Ltd. for the LOT190D main steam isolation valves and full load isolation valves of Units 5 and 6 of the Fangchenggang project. In 2024, a total of 54 sets of LOT190D main steam isolation valves and full load isolation valves were respectively signed with China General Nuclear Power Engineering Co., Ltd. for Units 1 and 2 of the Zhaoyuan project and Units 3 and 4 of the Taipingling project.
At present, only Dalian Dagao and CNNC Su Valve have independently developed pneumatic hydraulic actuators for main steam isolation valves and main feedwater isolation valves in China. The successful development of this achievement has broken through the technical bottleneck of pneumatic hydraulic actuators for main steam isolation valves and main feedwater isolation valves in China, and has the conditions for application in CAP1400, CAP1000, and AP1000 nuclear power units. It is not only of great significance for achieving 100% localization of CAP1400 third-generation nuclear power plant equipment, but also for promoting the independent nuclear power brand of CAP1400 to go global and gradually enter the international market.
Intellectual property situation: The independently developed intellectual property achievements of the main steam isolation valve and main feedwater isolation valve gas-liquid linkage actuator project have been searched and analyzed for patents at home and abroad, and no obstacle patents have been found. The intellectual property achievements of the project are independent and controllable. One utility model patent (a hydraulic control system for a gas-liquid linkage drive device) has been applied for and authorized, and three invention patents (a gas-liquid linkage actuator for the main steam isolation valve of a nuclear power plant, a gas-liquid linkage drive device suitable for the main steam isolation valve, and a hydraulic control system for the gas-liquid linkage drive device) have been authorized. Published a paper titled 'Structural Optimization and Stress Analysis of Pneumatic Hydraulic Drive Device Based on Modal Analysis' in the Journal of Mechanical Engineers.
Editor: Li Yuhang
Verified by: Xia Yuanhong
Reviewed by: Wang Shuai
Department: Technical Development Department
Date: June 7, 2025