With the development of the LNG industry, the demand for cryogenic emergency shut-off valve has increased, and the requirements of cryogenic emergency shut-off valve are also higher.
Introduction to LNG
Liquefied natural gas is referred to as LNG. It becomes a liquid after being compressed and cooled to its boiling point (-161.5°C). The valves used need to undergo low-temperature cryogenic treatment to relieve stress, ensure the low-temperature performance of the material, and ensure the finishing size. When the valve is in low temperature condition, the leakage caused by deformation caused by temperature change.
As an efficient and storable clean energy, LNG shows broad development prospects in all aspects of the industrial chain. China's natural gas liquefaction plants are mainly small-scale, and the largest processing scale in Huanggang, Hubei has reached a liquefaction capacity of 1.2 million tons/year. The scale of China's LNG terminal reserves is also expanding. Up to now, CNOOC has put into operation 6 LNG terminals, with an annual LNG receiving capacity of more than 24 million tons per year.
In the rapid development of the LNG industry, the demand for its supporting cryogenic valves (such as cryogenic globe valve, cryogenic ball valve, cryogenic safety valve, cryogenic check valve, cryogenic booster valve, cryogenic pressure reducing valve, cryogenic emergency shut-off valve) is increasing day by day . Because LNG has the remarkable characteristics of flammable and explosive ultra-low temperature, and LNG plants are usually located in the seaside salt spray environment, higher requirements are put forward for the selection and design of cryogenic valves.
Application of cryogenic valve in LNG plant
In small natural gas liquefaction plants, low-temperature valves are mainly concentrated in the liquefaction unit and LNG storage unit. The pressure level is not high and the inner diameter is small. Among them, the more severe working conditions are the mixed refrigeration cycle process, and the low-temperature mixed refrigerant throttle valve is also used for LNG throttling. This kind of multi-stage pressure-reducing regulating valve. According to rough statistics, the number of cryogenic valves used in general liquefaction plants accounts for about 30% of the total number of valves in the entire plant. In LNG receiving stations (mainly refers to large stations with a receiving capacity of more than 2 million tons/year), the number of cryogenic valves is about 2,000, of which the number of small-sized valves is about 700, and cryogenic valves account for more than 90% of all valves. The valve has a higher pressure rating and a larger diameter.
Basic requirements for cryogenic emergency shut-off valve in LNG field
The cryogenic emergency shut-off valve in LNG field should meet the following basic requirements:
1. The low temperature valve needs to lengthen the bonnet, and the bonnet should be an integral bolt connection structure;
2. It should be equipped with an extended valve stem to ensure that the packing is at ambient temperature, and all valve stems are of anti-blowout structure.
3. The valve trim should be easy to disassemble, especially the valve seat can be maintained online and easy to replace, and the trim and seal can be quickly disassembled from the top of the valve, which can be repaired online.
4. The valve with soft sealing structure should adopt fireproof design.
5. All ball valves should be equipped with pressure relief devices.
6. Ball valves and globe valves with external sealing structure should have external sealing performance.
7. The valve body, internal parts, valve cover, valve stem, actuator, etc. must be designed with anti-static structure.
Cryogenic Emergency Shut-off Valve Supplier - XINLIANTONG
Chengdu XinLianTong cryogenic equipment Co.,Ltd mainly engaged in the manufacture and development of cryogenic equipment system. Our company has the excellent management team, scientific production management, several high grade senior engineers and technicians. Our company has become a international leading manufacturer of low temperature thermal insulation pipe and low temperature equipment with AX production license for special equipment. If you want to purchase cryogenic emergency shut-off valve, please contact us.
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