| Abstract: | pVTt has been employed as the primary gas flow standard in many countries and the performance of the inlet valve significantly influences the verification. This paper not only proposes a hydraulically powered fast switching 3-way valve but also introduces its structure and working principle. Furthermore, it builds up the flow field simulation model and conducts the dynamic simulation of its working process. As shown by the results, the designed fast switching 3-way valve could achieve the fast switching of the critical flow. In addition, the “overlapping” mode and the “non-overlapping” mode of the 3-way valve are analysed contrastively. The result reveals that the flow field of the “non-overlapping” mode is more stable. Finally, the device is tested according to the pVTt verification procedure. As indicated by the results, the switching time of two fast switching 3-way valves corresponding to DN150mm and DN100mm caliber could be controlled within 55 ms, which is consistent with the simulation results. |
