江蘇華譽自動化設備制造有限公司
主營:電動執行機構 | 氣動執行機構 | 調節閥 | 旁路裝置 | 減溫減壓裝置 | 壓力匹配器18733303903
Consultation Hotline
江蘇華譽自動化設備制造有限公司
主營:電動執行機構 | 氣動執行機構 | 調節閥 | 旁路裝置 | 減溫減壓裝置 | 壓力匹配器18733303903
Consultation HotlineWith the development of the natural gas pipeline industry, the usage of natural gas pipeline valves is increasing, and natural gas pipeline valves are different from ordinary valves. Specifically, there are the following points:
1. Quick action, automatic shutdown
Due to the fact that management and control personnel are generally in the station or central control room, it is required that in the event of a major accident such as pipeline rupture, the pipeline valves can be automatically cut off. Pipeline valves require low operating force to achieve accurate operation when temperature and external force changes have an impact. Especially for emergency shut-off valves, they must be able to remain fully open for a long time and quickly lock the pipeline if necessary. At the same time, it is required that the opening and closing position and opening indicator of the valve be accurate and easy to understand, and meet the appropriate switching speed.
2. Electric actuators or pneumatic devices, pneumatic hydraulic linkage or electro-hydraulic linkage devices, with high output torque and explosion-proof performance
Due to the high delivery pressure, large diameter, and fast opening and closing time of the pipeline, the pipeline valve needs to use a high torque drive device. Such as electric actuators or pneumatic devices, pneumatic hydraulic linkage or electro-hydraulic linkage devices. Electric actuators or pneumatic devices also have explosion-proof requirements, requiring EExdIIBT4 and protection level IP68.
3. Low leakage
Most natural gas pipelines are built on the edge of cities, and their operation and management are not like ordinary factories. Workers often operate, maintain, and inspect them. Generally, urban natural gas pipelines are over a hundred kilometers long and can only be regularly patrolled and inspected. Moreover, sometimes pipelines need to pass through complex areas, and leakage of the medium may lead to serious fire accidents. Especially for pipelines close to cities, it is particularly important to prevent valve leakage.
The leakage requirements for natural gas valves are very strict, and usually buried and important valves adopt a fully welded valve body structure. In order to ensure the sealing performance of pipeline valves, the sealing pair is required to have excellent corrosion resistance, wear resistance, self lubrication, and elasticity. In recent years, the development of polymer materials has provided a broad field for the selection of pipeline valve sealing materials, such as polytetrafluoroethylene, nylon, nitrile rubber (NBR), special synthetic rubber (VITON), etc.
4. Corrosion resistant materials
Due to the fact that natural gas transported by pipelines contains a large amount of hydrogen sulfide (a toxic and highly corrosive gas that reacts with iron to form iron sulfide, which can flake and corrode mechanical equipment) before desulfurization. Even natural gas treated with desulfurization and other processes still contains residual hydrogen sulfide. Therefore, the selection of pipeline valves should be made of corrosion-resistant and sulfur resistant materials.
5. Long service life
Once the pipeline is put into operation, it is not allowed to stop running for a few years. The longer the operation time, the better. Unlike general chemical plants or refineries, there is a major overhaul period. The natural gas transported by pipelines faces a large number of users in the entire city, including residents, enterprises, factories, etc., especially those who use natural gas as raw material, and cannot be interrupted for a moment. Once the pipeline valves connected in series fail, the consequences are unimaginable. Therefore, the main sealing vulnerable parts of pipeline valves, such as valve seats, require a long service life. The service life of valves in general trunk pipelines is required to be over 30 years.