LNG Valve
LNG valves are key components in LNG production, reception, transportation and gasification.
LNG valves include cryogenic gate valves, cryogenic stop valves, cryogenic check valves and other types.
Cryogenic gate valves are mainly used for cutting in pipelines. The fluid resistance is small. The external force required for opening and closing is small. The medium flow direction is not restricted. The sealing surface is eroded when fully open. The body is simple and the casting process is good.
Cryogenic stop valves are only suitable for full opening and full closing. Adjustment and throttling are not allowed. The structure is simple, the manufacturing and maintenance are convenient, the working stroke is small, the opening and closing time is short, the sealing is good, the friction between the sealing surfaces is small, and the service life is long.
Cryogenic check valves prevent the backflow of pipeline media. The structure is simple, the manufacturing and maintenance are convenient, and the friction between the sealing surfaces is small and the service life is long.
Cryogenic check valves prevent the backflow of pipeline media. The structure is simple, the manufacturing and maintenance are convenient, and it can be installed horizontally and vertically.
When selecting LNG valves, the working conditions, applicable media, working pressure, and medium temperature should be confirmed according to the place of use and purpose to determine the nominal diameter, connection method, drive method, valve type, use form, shell and internal materials, sealing performance requirements, protective coating requirements, packaging and transportation requirements, and special structural length and other parameters and installation position and direction that match the pipeline.
Daily use of LNG valves should prevent misoperation. In low temperature seasons, pay attention to antifreeze and deal with valve leakage in time. The valve packing gland should not be pressed too tight. Generally, the packing should not be replaced or added under pressure.
Maintenance and disassembly of valves must be carried out under specified conditions. Electric or pneumatic devices must have safety isolation measures. When disassembling, place the valve in the fully closed position and slowly loosen the flange bolts. After disassembly, place it in a suitable place. When reassembling, pay attention to the direction of stop valves, throttle valves, pressure reducing valves, check valves, etc. Reverse installation will affect the effect. The installation position should be convenient for operation. Gate valves cannot be installed upside down.
