Double Stage Vacuum and Single Stage Vacuum

In the selection process of Vacuum Oil Purifier for transformer oil/insulating oil, we often hear the types of "single-stage Vacuum Oil Purifier" or "double-stage vacuum oil purifier". Do you know the difference between this double-stage and single-stage? And their applications ?

Here we share with you about the vacuum stages of Transformer Oil Filtration Machine.

The single-stage vacuum is only a rotary vane vacuum pump, and the double-stage vacuum has one more roots booster pump than the single-stage vacuum, which can greatly increase the vacuum value inside degassing chamber, therefore to achieve a better result of oil dehydration and oil degassing.

1- Double-stage vacuum oil purifier is mainly used in above 110kv substations and power transformers, because for such high voltage transformers, the requirements of oil dehydration and dielectric strength is higher, there must be sufficient vacuum to ensure that the oil and gas are fully evaporated to achieve oil-water separation and oil-gas separation, thereby to greatly improve the dielectric strength and breakdown voltage of transformer oil/insulating oil. Usually, the breakdown voltage can be improved from 20KV to above 75 KV by a double-stage vacuum oil purifier.

2- Single-stage vacuum oil purifier is mainly used for below 110KV subsations and power transformers, such as 66KV and below. The dielectric strength and breakdown voltage of transformer oil purified by a single-stage vacuum oil purifier will be a little lower than purified by a double-stage vacuum oil purifier. The breakdown voltage can be improved to above 60KV by a single-stage vacuum oil purifier.