It is widely used in pipelines with low pressure, large diameter, large dislocation and frequent loading and unloading, especially for the connection between mud tanks of solid control systems in the petroleum industry. The connecting pipeline can be made of glass steel pipe or rubber hose with joints at both ends. The glass steel pipe is corrosion-resistant, easy to handle, and the rubber pipe can be bent, which is suitable for dislocation installation of pipelines on site.