Vacuum pump leakage is caused by the following reasons
1. The vacuum pump is not tightly sealed: tighten all the connecting bolts, tighten the packing gland, and tightly wrap the pipe and the place where the instrument is connected to other components. Or replace the gasket and packing. For air leaks, you can also apply limestone, etc. as a temporary remedy.
2. Bearing skew: This phenomenon causes the impeller to be installed in the pump body obliquely. For a single-acting pump, the axial clearance is not uniform. When Ye Yan rotates, a part of it will inevitably rub against the side cover, scratch the side cover and the end face of the impeller, and increase the axial clearance. When the gas in the compression chamber passes through the enlarged gap, a large amount of gas leaks into the suction chamber, which reduces the degree of vacuum or the exhaust pressure. At this time, the bearing should be removed for repair, and then installed correctly.
3. The front and rear side covers are not concentric: it is possible that the front and rear side covers of the vacuum pump have a large non-axiality, and the result is the same as the skew of the bearing.
4. The vacuum pump is heated: the temperature of the vacuum pump increases, and the saturated vapor pressure also increases, which will reduce the vacuum degree, but this has no effect on the exhaust pressure.