The "Guardian" of Cryogenic Valves: Shanghai Raido Metal Sealing Rings Key Challenges for Cryogenic Valves
Created on 11.04
In the industrial sector, cryogenic valves play acrucial role, widely used in scenarios such as the production, storage andtransportation of liquefied natural gas (LNG), air separationequipment, and scientific research. In these applications, valves arerequired to control the flow of cryogenic media such as liquid air, liquidoxygen, liquid nitrogen, and liquefied natural gas. However,under extremely low-temperature environments, the sealing of cryogenic valvesfaces a series of severe challenges.
When the temperature drops to an extremely low level,ordinary sealing materials undergo changes in physical properties. For example,common rubber sealing materials harden and become brittle rapidly at lowtemperatures, losing their original elasticity and flexibility, which leads toa significant decline in sealing performance and inability to effectivelyprevent medium leakage. Moreover, cryogenic media often have special chemicalproperties—some are highly oxidizing, such as liquid oxygen, while others arecorrosive, like certain cryogenic liquids. These characteristics requiresealing materials to withstand not only the test of low temperatures but alsochemical erosion; otherwise, they are prone to corrosion and damage,triggering potential safety hazards. In addition, cryogenic valves also need towithstand pressure changes during operation, and frequent opening and closingoperations exert mechanical stress on sealing components. Under the combinedaction of low temperature and pressure, the reliability of the sealingstructure faces great challenges. Once the seal fails, it may cause theleakage of cryogenic media, which not only results in energy waste but also maytrigger serious safety accidents such as fires and explosions, posing a hugethreat to personnel and equipment.
Dilemma of Ordinary Sealing Rings at Low Temperatures
Facing the sealing requirements of cryogenic valves,ordinary sealing rings expose many insurmountable defects. In terms of materialproperties, common ordinary rubber sealing rings, whose main component is highmolecular polymer, see a sharp decrease in the mobility of molecular chains atlow temperatures. This enhances the intermolecular forces of rubber, makingthe originally soft and elastic rubber gradually become stiff and hardened.When the temperature drops to a certain level, ordinary rubber sealing ringsbecome extremely brittle and are prone to cracking under slight externalforces, such as mechanical stress generated by valve opening and closingactions, resulting in complete loss of sealing function.
Chemical stability is another major problem forordinary sealing rings at low temperatures. Thechemical activity of cryogenic media may change under low-temperatureenvironments; some media that are relatively chemically stable under normalconditions may erode ordinary sealing materials at low temperatures. Ordinaryrubber sealing rings lack sufficient chemical erosion resistance. When exposedto highly oxidizing liquid oxygen, the double bonds in rubber molecules areeasily oxidized, leading to material aging and deterioration, and a subsequentdecline in sealing performance. When facing corrosive cryogenic liquids,ordinary rubber is more likely to be corroded and dissolved, failing tomaintain the integrity of the sealing structure and thus causing mediumleakage.
In addition, ordinary sealing rings have poorfatigue resistance at low temperatures. Frequent opening and closingoperations of cryogenic valves subject ordinary sealing rings to continuousalternating stress. In low-temperature environments, ordinary sealing rings,due to reduced elasticity, cannot effectively buffer such stress changes, andcracks are prone to occur in stress-concentrated areas. With the increase inthe number of opening and closing cycles, the cracks gradually expand,eventually leading to complete damage of the sealing rings, which greatlyshortens their service life and fails to meet the demand for long-term stableoperation of cryogenic valves.
Performance Advantages of Shanghai Raido Metal Sealing Rings
(1) Excellent Low-Temperature Resistance
In the application of cryogenic valves, Shanghai Raidometal sealing rings demonstrate unparalleled low-temperature resistance. Whenin an extremely low-temperature environment of -196℃, ordinary sealingmaterials have long lost their sealing capacity due to the low temperature, butShanghai Raido metal sealing rings can maintain good strength. This isattributed to their special metal material formula and precision manufacturingprocess, which ensure that their internal crystal structure remains stable at lowtemperatures, effectively inhibiting the embrittlement of the material. Evenunder frequent temperature fluctuations, they can always maintain stablesealing performance, ensuring the reliable operation of cryogenic valves inultra-low temperature environments and avoiding medium leakage caused by sealfailure.
(2) Strong Chemical Resistance
These metal sealing rings possess strong chemicalresistance and can withstand chemical erosion from various cryogenic media.When exposed to highly oxidizing liquid oxygen, they will not be oxidized anddamaged like ordinary materials; the dense oxide film formed on their metalsurface can effectively prevent further oxidation reactions and maintainmaterial integrity. For corrosive cryogenic liquids, they rely on their stablechemical properties and do not react chemically with or dissolve in these media,ensuring that the sealing performance is not affected by chemical factorsduring long-term use. Whether in common cryogenic media such as liquid oxygenand liquid nitrogen, or in other cryogenic liquid environments with specialchemical properties, Shanghai Raido metal sealing rings can work stably,providing reliable sealing guarantee for cryogenic valves and greatly extendingthe service life of valves in complex chemical environments.
(3) High Strength and Long Service Life
Shanghai Raido metal sealing rings have excellentcompressive strength and fatigue resistance, which are key to ensuring thelong-term stable operation of cryogenic valves. During the operation ofcryogenic valves, they often face large pressure differences, and these sealingrings can withstand such high pressure differences without deformation ordamage, ensuring the sealing effect of the valve under different pressureconditions. At the same time, during frequent opening and closing operations,ordinary sealing rings are prone to cracks or even breakage due to fatigue, butShanghai Raido metal sealing rings can withstand tens of thousands of openingand closing cycles with their outstanding fatigue resistance. Under appropriateworking conditions, they can be used continuously for many years withoutreplacement, which greatly reduces maintenance costs and equipment downtime,improves the efficiency and economy of industrial production, and providessolid support for the efficient operation of cryogenic valves.
Practical Application Cases
The application effect of Shanghai Raido metal sealingrings in cryogenic valves of liquid nitrogen storage equipment is remarkable. Alarge chemical enterprise's liquid nitrogen storage system needs to open andclose valves frequently every day to transport liquid nitrogen. In the past,when using ordinary sealing rings, the seals had to be replaced every 2 monthson average, which not only incurred high maintenance costs but also posed therisk of liquid nitrogen leakage due to seal failure. After adopting ShanghaiRaido metal sealing rings, during 5 years of operation, the sealing rings stillmaintained good sealing performance without any leakage problems, which greatlyimproved the operational stability and safety of the liquid nitrogen storageequipment and saved the enterprise a large amount of maintenance costs andeconomic losses caused by equipment shutdown.
Their performance advantages are also prominent in theapplication of cryogenic valves in liquid oxygen transmission pipelines. Theliquid oxygen transmission pipeline of an aerospace fuel supply base operatesat a pressure as high as 10MPa and a temperature as low as -196℃. Before usingShanghai Raido metal sealing rings, ordinary sealing rings frequently sufferedfrom corrosion and seal failure due to their inability to withstand the strongoxidizing property of liquid oxygen and the low-temperature and high-pressureenvironment, which seriously affected the safe transmission of liquid oxygen.After replacing with Shanghai Raido metal sealing rings, after more than 3years of continuous operation, these metal sealing rings successfully withstoodthe chemical erosion of liquid oxygen and the test of low temperature and highpressure, maintaining stable sealing performance, ensuring the safe andreliable transmission of liquid oxygen, strongly guaranteeing the stability ofaerospace fuel supply, and providing solid support for the smooth developmentof relevant scientific research and production activities.
Conclusion and Outlook
To sum up, metal sealing rings, especially ShanghaiRaido metal sealing rings, play a key role in the sealing application ofcryogenic valves, successfully overcoming many drawbacks of ordinary sealingrings in low-temperature environments. Their excellent low-temperatureresistance, strong chemical resistance, high strength, and long service lifemake them an important guarantee for the reliable operation of cryogenicvalves. They also demonstrate significant advantages in practical applicationcases, effectively improving the operational stability and safety of relevantequipment and reducing maintenance costs.
Looking forward, with the growing global demand forclean energy, such as the continuous expansion of the LNG industry, and thein-depth development of fields such as aerospace and cryogenic scientificresearch, the demand for cryogenic valves and high-performance sealingmaterials will become increasingly strong. Relying on their unique performanceadvantages, metal sealing rings are expected to be widely applied in moreemerging low-temperature fields, further promoting technological progress anddevelopment in related industries. At the same time, with the continuousinnovation of materials science and manufacturing processes, the performance ofmetal sealing rings will be continuously optimized and improved, providing moresolid support for the efficient and safe operation of low-temperatureindustrial equipment and playing a more important role in future industrialdevelopment.