Natural gas transported by pipeline contains a large amount of hydrogen sulfide (a toxic and highly corrosive gas) before desulfurization. Even the natural gas that has undergone desulfurization and other processes still has residual hydrogen sulfide. Therefore, the selection of pipeline valves should be corrosion-resistant and sulfur-resistant materials.
Generally, urban natural gas pipelines are more than 100 kilometers long, and can only be patrolled and inspected regularly. Sometimes pipelines need to pass through areas with complicated conditions, and the leakage of medium may cause serious fire accidents. Especially for pipelines close to the city, it is particularly important to prevent the leakage of the valve.
Once the pipeline is put into operation, it is not allowed to stop operation within a few years, and it is not allowed to have a momentary interruption, and there is no major repair period. Once the pipeline valve in series on the pipeline fails, the consequences are unimaginable. Therefore, the wearing parts of pipeline valves require long service life.
The control personnel are generally in the station or the control room, which requires reliable control performance of the valve, and requires the valve itself to have protection and explosion-proof measures. Especially the long-open valve requires accurate cut off in the sudden change of the situation. Therefore, reliable control performance becomes the focus.