Vacuum pump maintenance experts guide how to judge whether the vacuum pump has air leakage

To be honest, the occurrence of many failure problems of vacuum pumps has nothing to do with the geographical problems of users. Just like the leakage of vacuum pumps, this is an internal problem. In general, what are the parts of vacuum pumps that are prone to leakage? And if there is leakage, we will How to solve it? Before solving it, we need to know whether the vacuum pump has air leakage. Therefore, this article will be guided by vacuum pump maintenance experts on how to judge whether the vacuum pump has air leakage, and summarize some reasons for air leakage.

The parts that are prone to air leakage of the vacuum pump are: the starting and closing parts of the welding seam, the intersection of two welding seams, the welding part of the bellows, the welding seam of the pipe joint, and the brazing seam affected by the movement. If the flange seal or dynamic seal is carefully cleaned before installation and the assembly is reasonable, this part is not easy to leak. Metal-ceramic, metal-glass seals, such as lead-out electrodes, high-voltage leads for regulation, pins, caps, etc. Welds affected by cold and thermal shock.

The vacuum pump maintenance experts guide how to judge whether the vacuum pump has air leakage. The summary is as follows:

1. Check whether the gravity return water of the vacuum pump speed regulating feed pump can be introduced into the condenser. If the return water volume is small and the water sealing bag cannot be sealed, the gravity return water of the sealing water of the feed pump should be poured into the ditch.

2. Check that the vacuum damage door is closed and does not leak.

3. Check whether there is air leakage at the connection between the extraction pipeline of the vacuum pump and the cylinder. Here, the vacuum decreases when the load decreases, and the vacuum increases slightly after the load increases.

4. Check that the drain valve on the steam side of the condenser is closed and does not leak.

5. Check whether the water level of the low-pressure heater under negative pressure is normal, and whether the drain door is tight.

6. Check that the water level gauge of the vacuum system is not broken or leaked.

7. Check whether the water seal, pipeline, flange or welding joint of the vacuum system valve is not tight, especially the pipeline and valve port from the expansion box or the boiler start-up separator to the condenser.

8. Check the vacuum pump low-pressure cylinder exhaust safety door.

The vacuum pump maintenance manufacturer shows that the general vacuum pump leakage is caused by the following conditions.

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 uneven. 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 heats up: 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.