The natural gas transported by pipelines contains a large amount of hydrogen sulfide (a toxic and corrosive gas that reacts with iron to form iron sulfide, which peels off in flakes and can corrode mechanical equipment) before desulfurization. Even natural gas treated with desulfurization and other processes still has residual hydrogen sulfide. Therefore, the selection of pipeline valves should use corrosion-resistant and sulfur resistant materials.

Leakage rate of natural gas valves:

The leakage rate of natural gas valves is strictly required, and important valves and those that are usually buried underground use a fully welded valve body structure. In order to ensure the overall sealing performance of pipeline valves, it is required to seal them with excellent wear resistance, self lubrication, corrosion resistance, and elasticity. In recent years, the rapid development of polymer materials has provided a broad selection space for pipeline valve sealing materials, such as polytetrafluoroethylene, nitrile rubber (NBR), nylon, special synthetic rubber (VITON), etc.

Most natural gas pipelines are built on the outskirts of cities, and their management and operation are not like typical factories, where workers often maintain, operate, and inspect them. In general, urban natural gas pipelines are over hundreds of kilometers long and can only be inspected and patrolled regularly. Moreover, sometimes pipelines need to pass through complex areas, and the leakage of media may cause serious fire accidents. Especially for pipelines closer to cities, preventing valve leakage is particularly important.

Natural gas valve drive device:

Due to the large diameter, high pressure, and fast opening and closing time of pipeline transportation, pipeline valves require the use of high torque drive devices. Such as pneumatic or electric devices, electro-hydraulic linkage or gas-liquid linkage devices. The driving device also needs to have explosion-proof requirements, requiring EExd IIB T4 and a protection level of IP68. Due to the fact that management and control personnel are usually located in the central control room or within the station, 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 must require low operating force to achieve accurate operation when affected by temperature and external force changes. Especially for emergency shut-off valves, they must be able to remain fully open for a long time and quickly lock the pipeline when necessary. At the same time, it is also required that the opening and closing position and opening indicator of the valve be easy to understand and accurate, and meet the appropriate opening and closing speed.

Application scenarios of natural gas valves:

Once the pipeline is put into operation, it is not allowed to stop running for several years. The longer the operation time, the better, unlike typical refineries or chemical plants that have major maintenance periods. The natural gas transported by pipelines faces a large number of users in the entire city, including residents, factories, enterprises, etc. Especially for enterprise users who use natural gas as raw material, there should be no momentary interruption. Once the pipeline valves connected in series fail, the consequences can be unimaginable. Therefore, the main sealing vulnerable parts of pipeline valves, such as valve seats, require a longer service life. The service life of valves in general trunk pipelines is required to be over 30 years.