Abstract: To explore the vacuum pump equipment and pipeline structure performance of low vacuum pipeline system in specific conditions, the experiment platform of low vacuum pipeline system was set up in this paper. The experimental study was carried out on vacuum pump equipment performance and pipeline structure deformation law based on the platform, and the following conclusions were reached. The tube wall compressive strain increases with the increase of the absolute value of relative vacuum degree. The increase of the absolute value of relative vacuum degree can reduce the tensile strain caused by the increase of temperature in the tube, while the increase of temperature is beneficial to reduce the compressive strain caused by the increase of relative vacuum degree. When the cooling circulation system is used, the extraction rate of the vacuum pump is basically constant at different temperatures. In different vacuum circumstance the rising rate of temperature heated by the shortwave twin-tube is basically constant. The vacuum can reduce the internal temperature of pipeline structure to some extent under the condition of temperature difference between inside and outside. When cyclic loading is applied, the rebound of structural strain is greater than the initial value after unloading the vacuum.

Key words: low vacuum, vacuum pump, pipeline, mechanical property, cyclic loading