Gaseous ethane pipeline transportation stopping and restarting system

The utility model discloses a gaseous ethane pipeline transportation stopping and restarting system which comprises a main line starting point valve set, a temperature pressure flow detection system,a main line tail end valve set, a temperature pressure flow detection system, a main line tail end bypass valve set and a heat tracing pipeline system. The utility model can satisfy the following requirements: 1) the ethane pipeline improves the operation pressure, allows the pipeline to form liquid ethane when stopping conveying, and reduces the pipe diameter; (2) in the restarting process, whengaseous ethane enters from the upstream, ethane is discharged through a bypass to control the ethane gas discharge capacity, heat exchange between newly-fed ethane and accumulated ethane is achieved,and liquid ethane is slowly vaporized and accumulated by reducing the pressure of a pipeline by a small amount; 3) in the restarting process, the stainless steel valve group and the heat tracing system are bypassed, so that the low-temperature influence of the throttled ethane on the pipeline system is avoided, the temperature of the pipeline system is increased to a certain extent, and the low-temperature influence of the throttled ethane on a downstream system is avoided, and 4) in the restarting process, the ethane continuously discharged in the starting process can enter the downstream system.