How can molten salt valves meet the demands of both reliability and cost?

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**The \"Several Opinions on Promoting the Large-Scale Development of Concentrated Solar Power Generation\" (Document No. 1645), jointly issued by the National Development and Reform Commission and the **Energy Administration, serves as a guiding document for China’s concentrated solar power industry as it moves from experimental phases to large-scale development. It provides a clear roadmap and implementation strategies for the industry’s growth. In this context, the molten salt valves, which serve as the core control elements of solar thermal power plants, their localization and improved quality have become key factors for reducing costs and increasing efficiency in these industries, as well as for ensuring safe and stable operation. As a key component in concentrated solar power generation, molten salt valves must withstand daily start-up and shutdown cycles, frequent temperature fluctuations during operation, as well as the complex operating conditions resulting from different operational strategies and heat collection methods. At present, the core technology for molten salt valves remains in the hands of a very few foreign brands; not only are the prices high and the delivery times long, but the cost of spare parts is also elevated. Although domestic molten salt valves have made breakthroughs in terms of application, they generally suffer from issues such as a short operational lifespan and insufficient technical expertise. Coupled with low-price competition in the market, their potential risks cannot be ignored. The problem lies not only in the possible extension of the system debugging period by one or two months, or even longer – this is merely the beginning of the challenges ； The performance degradation after commissioning, the frequent failures, and the high maintenance costs resulting therefrom far exceed the savings achieved during the bidding process; ultimately, the cost savings obtained have to be repaid at a cost many times higher. To meet the demands of the scaled development of the concentrated solar power generation industry, molten salt valves need to overcome the following key challenges at their core: First, the reliability of molten salt valves in critical locations must be improved; failures of these valves can lead to system shutdowns, and their reliability is directly related to the overall operational safety of the power plant. For example, downflow control valves used in molten salt systems commonly face industry-related issues such as high pressure differences, poor flow regulation accuracy, difficulties in controlling the pressure difference downstream of the valve, significant operational vibration, and severe salt leakage. There is an urgent need for mature and reliable solutions to be developed through multiple projects and extended periods of practical testing, in order to fundamentally prevent unplanned system shutdowns caused by valve failures. II. Strengthening the safety barrier to address safety risks under extreme operating conditions: Special attention must be paid to the safety issues related to molten salt valves in certain locations. Taking the check valve at the cold pump outlet as an example, in the event of a sudden shutdown of the pump, the impact force generated by the large pressure difference behind the valve theoretically poses a risk of the valve cover being ejected. Although the probability of occurrence is extremely low, given the requirement for intrinsically safe operations in solar thermal power plants, such risks must be completely eliminated through measures such as structural optimization, material upgrades, and redundant design. III. Overcoming structural constraints and innovating solutions to the persistent problem of internal leakage in large-diameter valves. At present, three-eccentric butterfly valves are commonly used in large-diameter molten salt pipelines; however, as seen in projects that have been put into operation, serious internal leakage problems persist even when imported brands are used. From a structural perspective, current domestic products and imported products use similar designs, making it difficult to avoid this inherent flaw. Domestic manufacturers urgently need to break away from traditional structural frameworks, increase investment in research and development, and explore structural innovations for triple-eccentric butterfly valves in order to resolve the issue of internal leakage at its root. IV. Improve maintainability and interchangeability to reduce operational costs over the entire life cycle. The maintainability and interchangeability of the main components of molten salt valves are key factors affecting the efficiency and costs of plant operation and maintenance. During long-term operation, molten salt valves are subject to factors such as erosion by frozen salt and corrosion by the medium, which inevitably lead to problems like internal leakage. If core components such as the valve seat and valve stem are not repairable, the entire valve must be discarded and replaced after a failure occurs ； Moreover, if components of the same model and specification are interchangeable, spare parts can be quickly replaced in case of a failure, significantly reducing downtime. Industry expert Chen Jinhuan points out that a failure of a molten salt valve can cause the system to be shut down for over a month or even longer; if attention is not paid to the repairability and interchangeability of key components, the operational costs throughout the product’s lifetime will increase significantly. The complex operating environment of concentrated solar power generation requires that key equipment eliminate risks at their source and ensure intrinsical safety, which depends on long-term experience accumulation. Experience cannot be replicated in a short time, nor can it be compensated for by mere technical skills; it takes time to develop and practical experience across multiple projects to be forged. Only by firmly grounding themselves in project practices and continuously overcoming technical bottlenecks can domestic brands help the industry achieve its goals of reaching parity between installed capacity and levelized cost of electricity by 2030. This will also facilitate the full localization of key equipment, thereby laying a solid industrial foundation for the large-scale development of concentrated solar power generation.