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| Quantity: | |
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Z41H
ZJFV/OEM
The special material selection and structural design that need to be considered in the design of low-temperature steel valves include:
1. Material selection: Low temperature valves usually use materials with good low-temperature performance, such as austenitic stainless steel (such as 304, 316L, 310S, etc.), which can still maintain sufficient toughness and strength at low temperatures. For more extreme temperatures, special alloy steels or nickel based alloys may be required. Non metallic materials such as PCTFE (trifluorochloroethylene polymer) and flexible graphite are also commonly used as seals for low-temperature valves because they can maintain good performance at low temperatures.
2. * * Valve Cover Elevated Structure * *: In order to protect the packing and operating mechanism from low temperatures, the valve cover of low-temperature valves is usually designed with a long neck structure to ensure that the packing box is away from the low-temperature medium, prevent freezing, and extend the service life.
3. Drip tray structure: A drip tray is installed on the valve cover to reduce the impact of low-temperature media on the valve stem and packing, and prevent corrosion of the flange bolts by liquefied water droplets.
4. * * Pressure relief hole design * *: In order to prevent abnormal pressure rise inside the valve due to medium gasification, a pressure relief hole needs to be added at the inlet of the low-temperature valve to connect the chamber and the inlet pipeline.
5. Anti static structure: Install conductive devices between the valve stem and valve body, as well as between the valve stem and the opening and closing components, to dissipate static electricity and avoid safety hazards.
6. * * Fireproof structure * *: The low-temperature valve adopts multiple seals in the middle passage to prevent internal leakage caused by the failure of the soft seal valve seat during a fire.
7. * * Inverted seal upward structure * *: Move the inverted seal upward to ensure that it works at room temperature and extends its service life.
8. * * Cryogenic treatment * *: Austenitic materials require cryogenic treatment during production to ensure sufficient internal structural transformation and improve the reliability of valves in low-temperature environments.
9. * * De oiling and degreasing * *: For low-temperature valves using liquefied natural gas (LNG), liquid hydrogen, liquid oxygen and other media, de oiling and degreasing cleaning is required to ensure the cleanliness and safety of the valve.
10. Valve body and stem design: The valve body should be able to withstand expansion and contraction caused by temperature changes, while the stem needs to be specially treated, such as chrome plating, nickel phosphorus plating, or nitriding treatment, to improve surface hardness and prevent biting with the packing.
11. Sealing surface design: The sealing surface of low-temperature valves is usually welded with hard alloy to improve wear resistance and sealing performance.
12. * * Gaskets and Fillers * *: Choose gasket materials suitable for low-temperature environments, such as flexible graphite or PTFE. The design of the packing box should ensure good sealing performance even at low temperatures.
These designs and material choices ensure the reliability and safety of low-temperature valves in extreme low-temperature environments.
The special material selection and structural design that need to be considered in the design of low-temperature steel valves include:
1. Material selection: Low temperature valves usually use materials with good low-temperature performance, such as austenitic stainless steel (such as 304, 316L, 310S, etc.), which can still maintain sufficient toughness and strength at low temperatures. For more extreme temperatures, special alloy steels or nickel based alloys may be required. Non metallic materials such as PCTFE (trifluorochloroethylene polymer) and flexible graphite are also commonly used as seals for low-temperature valves because they can maintain good performance at low temperatures.
2. * * Valve Cover Elevated Structure * *: In order to protect the packing and operating mechanism from low temperatures, the valve cover of low-temperature valves is usually designed with a long neck structure to ensure that the packing box is away from the low-temperature medium, prevent freezing, and extend the service life.
3. Drip tray structure: A drip tray is installed on the valve cover to reduce the impact of low-temperature media on the valve stem and packing, and prevent corrosion of the flange bolts by liquefied water droplets.
4. * * Pressure relief hole design * *: In order to prevent abnormal pressure rise inside the valve due to medium gasification, a pressure relief hole needs to be added at the inlet of the low-temperature valve to connect the chamber and the inlet pipeline.
5. Anti static structure: Install conductive devices between the valve stem and valve body, as well as between the valve stem and the opening and closing components, to dissipate static electricity and avoid safety hazards.
6. * * Fireproof structure * *: The low-temperature valve adopts multiple seals in the middle passage to prevent internal leakage caused by the failure of the soft seal valve seat during a fire.
7. * * Inverted seal upward structure * *: Move the inverted seal upward to ensure that it works at room temperature and extends its service life.
8. * * Cryogenic treatment * *: Austenitic materials require cryogenic treatment during production to ensure sufficient internal structural transformation and improve the reliability of valves in low-temperature environments.
9. * * De oiling and degreasing * *: For low-temperature valves using liquefied natural gas (LNG), liquid hydrogen, liquid oxygen and other media, de oiling and degreasing cleaning is required to ensure the cleanliness and safety of the valve.
10. Valve body and stem design: The valve body should be able to withstand expansion and contraction caused by temperature changes, while the stem needs to be specially treated, such as chrome plating, nickel phosphorus plating, or nitriding treatment, to improve surface hardness and prevent biting with the packing.
11. Sealing surface design: The sealing surface of low-temperature valves is usually welded with hard alloy to improve wear resistance and sealing performance.
12. * * Gaskets and Fillers * *: Choose gasket materials suitable for low-temperature environments, such as flexible graphite or PTFE. The design of the packing box should ensure good sealing performance even at low temperatures.
These designs and material choices ensure the reliability and safety of low-temperature valves in extreme low-temperature environments.
