Main Types of Transformer Oil Filtration Facilities

Learn the key types of transformer oil filtration systems — from single-stage vacuum units to full regeneration plants — and how each improves transformer reliability.

Introduction to the main types of transformer oil filtration equipment

 1. Single-Stage Vacuum Filtration

Basic dehydration and gas removal.

Use: Routine maintenance of small/medium transformers (≤110 kV).

Advantage: Compact, economical, easy operation.

 2. Double-Stage Vacuum Filtration

Deep purification through two vacuum chambers.

Use: Large or high-voltage transformers (≥110 kV).

Advantage: Removes moisture ≤3 ppm restores dielectric strength.

 3. Centrifugal Purification

Uses centrifugal force to separate free water and solids.

Use: Industrial or marine oil systems.

Advantage: Fast water removal, no filter elements.

 4. Adsorption / Regeneration System

Oil passes through adsorbents such as Fuller’s earth or silica gel.

Use: Aged or deteriorated transformer oil.

Advantage: Removes acids and color bodies, restores oil quality.

 5. Online Filtration Unit

Continuous circulation while the transformer remains energized.

Use: Critical substations or remote transformers.

Advantage: Maintains long-term oil cleanliness without shutdown.

 6. Combined Purification Plant

Integrates vacuum, filtration, and regeneration functions.

Use: Comprehensive treatment or waste-oil recovery.

Advantage: Produces near-new oil quality, fully automated.

Summary Table

|               Type                |      Main Function      |         Typical Use             |

| -------------------------- | ------------------------| --------------------------- |

| Single-Stage Vacuum    | Basic dehydration       | ≤110 kV transformers     |

| Double-Stage Vacuum  | Deep purification        | ≥110 kV transformers     |

| Centrifugal                    | Separate free water     | Industrial oil                    |

| Adsorption                    | Regeneration              | Aged oil                           |

| Online                           | Continuous filtration   | In-service units                |

| Combined                     | Full treatment              | Waste-oil recycling          |

Sino-NSH provides professional transformer oil filtration and regeneration systems worldwide.