How do transformer oil purification vacuum pumps work?

In a transformer oil purification system, vacuum pumps are used to remove dissolved gases and moisture from the oil. The pump creates a vacuum inside a chamber where the oil is heated. Under low pressure, the boiling point of water is reduced, allowing moisture and dissolved gases to evaporate. The vaporized gases and moisture are then extracted by the vacuum pump, while the purified oil is recirculated back into the transformer. This process improves the oil’s dielectric strength and insulating properties.