1. under the following circumstances, it is recommended to use constant pressure transmission plugging
The tube gas flow is larger (100 * 104m3/d), and to the important industrial users and the number of users is the gas; gas or natural gas purification plant gas (including raw gas and gas purification) only the input point of the pipeline network; the pipeline belongs to a single, unable to form a loop network and without auxiliary gas channel; for process equipment (such as a large number of problems off the valve internal leakage or operation failure), unable to stop the implementation of transport pipeline.
2. under the following circumstances, it is recommended to stop gas transformation
As with other pipelines in a small range of gas formed complementary, after the shutdown of the pipeline gas supply: the influence of small single user transmission, the amount is not large, the user is not strong dependence on natural lines, to do a short time to stop gas. Gas users, such as double Township civil, small chemical fertilizer users; the main gas source is the Sichuan Chongqing pipeline gas purification plant of the mine, when the purification plant maintenance (usually 1 times a year, each intake air intake point) re allocation, this task is largely part of the pipeline gas transportation bear reduction if the gas stop, but by other pipeline transport in pipe generation; the equilibrium point of the network (zero velocity), gas stop these paragraphs will not cause a big impact on the network operation of gas supply in a short period of time.