What are the cryogenic valves for LNG application
Time: July 11, 2020 13:54:19 Source: Yonglong Valve Reading: zero second
What are the cryogenic valves for LNG application
Low temperature valves used in LNG include low temperature stop valve, low temperature ball valve, low temperature stop valve, low temperature butterfly valve, low temperature check valve, low temperature gate valve, low temperature filter, low temperature stop valve, pneumatic emergency stop valve, electric emergency stop valve, low temperature electric ball valve, low temperature pneumatic ball valve, low temperature electric control valve, low temperature safety valve, low temperature pressure reducing regulating valve, low temperature pressure boosting regulating valve, Low temperature vacuum stop valve and other products.
Factors for cryogenic valve design:
Temperature has an important influence on valve design. For example, users may need it for hot environments such as the Middle East. Alternatively, it may be suitable for cold environments such as polar oceans. Both environments will affect the tightness and durability of the valve. The components of these valves include valve body, valve cover, valve stem, valve stem seal, ball valve and valve seat. Due to different material compositions, these parts expand and contract at different temperatures.
Low temperature valve application options:
1. Operators use valves in cold environments, such as oil drilling platforms in polar waters.
2. The operator uses the valve to manage the fluid whose temperature is far below the freezing point.
In case of highly flammable gas, such as natural gas or oxygen, the valve must also operate correctly in case of accident.
Low temperature valve pressure problem:
There is pressure accumulation during normal treatment of refrigerant. This is due to the increased heat of the environment and the subsequent formation of steam. Special attention needs to be paid when designing the valve/piping system. This allows pressure to build up.
Low temperature valve temperature problem:
Due to different material compositions and the length of time they are subjected to the refrigerant, each component of the cryogenic valve expands and contracts at a different rate.
Considering the cost of making gas into refrigerant first, leakage is very expensive and dangerous during the operation with liquefied gas.
A major problem of cryogenic technology is the possibility of valve seat leakage. They can avoid the above problems by underestimating the radial and linear growth of diameter related to the body and selecting the correct valve.
Extending the valve cover is a very important feature, because it determines the tightness of the stem sealant. The packing used to seal the valve stem is extended to the area with relatively normal temperature, which means that the seal of the valve stem must keep a certain distance from the cryogenic fluid, which can prevent the handle from freezing and failing to start.
Select valves for cryogenic media:
It is not complicated to select valves for low temperature applications. The buyer must consider the application pressure, use temperature, working space and control mode. Moreover, the specific nature of cryogenic fluids requires specific valve performance. Proper selection can ensure operation reliability, equipment protection and operation safety.
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