The vacuum globe valve can be used under negative pressure of 0.01MPa, which belongs to ultra-vacuum. If it is 0.1MPa, it belongs to low-pressure auxiliary vacuum, and low-pressure vacuum cannot maintain pressure under complete vacuum. For example, the rated negative pressure of vacuum system is 0,5mpa, at this time we can use ordinary globe valve, if the negative pressure is 0.1MPa. Then we should clearly choose the vacuum globe valve when selecting the model, and the maximum value of the vacuum negative pressure is 0.01MPa.
The leakage of the vacuum shut-off valve is because the connecting part of the rod is stuck, or there is no lubricating oil to control its sensitivity, or the packing part is loose. The screw can be locked at the pressure plate. If the packing is squeezed out after locking At this time, it is not a packing leakage. It may be due to various factors such as high pressure and high negative pressure. The installation must be low in and high out, and installation errors will also cause leakage.
