Transformer oil duct spacers are small but essential insulation components used in high-voltage transformers. These strips maintain consistent oil circulation channels between coil windings, preventing overheating and ensuring structural support. As part of the insulation system, they play a critical role in maintaining the transformer’s cooling and mechanical integrity.
Why Are Oil Duct Spacers Critical in Transformer Design?
Cooling and dielectric stability are key to transformer longevity. Oil duct spacers ensure:
- Optimized Oil Flow: Help create continuous cooling channels between windings for efficient heat dissipation.
- Mechanical Support: Prevent coil collapse or warping under axial forces or heat.
- Structural Reliability: Maintain consistent insulation gaps to prevent short circuits or hotspots.
- Compatible with oil-immersed and dry-type transformers alike.
Key Functions of a Transformer Oil Duct Spacer
- Cooling Channel Support
- Maintains consistent duct spacing
- Ensures free oil circulation to extract core heat
- Mechanical Separation
- Acts as an electrical insulation barrier
- Prevents contact between winding layers
- Structural Integrity
- Supports vertical winding structure
- Avoids coil shifting or deformation over time
Materials Commonly Used
Transformer oil duct support strips are made from high-dielectric, oil-compatible materials such as:
- Pressboard: IEC 60641 certified cellulose board, most commonly used in oil-filled systems
- Epoxy-coated kraft paper: Resin-enhanced for bonding and thermal resistance
- FRP composite: Used in high-mechanical load or high-temperature areas
- Pre-compressed insulation strips: High rigidity and stability under thermal cycling
Why Pressboard?
Pressboard has great oil absorption, strong mechanical strength, and flexible processing. This makes it the best choice for most medium- and high-voltage applications.
Standard Dimensions & Processing Formats
| Property | Typical Range |
|---|---|
| Thickness | 2 – 10 mm |
| Width | 8 – 40 mm |
| Length | 200 – 2000 mm |
| Edge Machining | Chamfered / Notched / Rounded |
Available Formats:
- CNC-cut insulation spacer strips
- Die-punched support blocks
- Pre-assembled oil duct spacer kits
- Custom grooved or slotted forms
Typical Applications in Transformers
These components are widely used in:
- Vertical duct channels between HV/LV windings
- Support blocks in rectangular or disc-type coils
- Oil gap regulation in dry-type transformer designs
- Cast-resin or epoxy-molded coil structures
👉 Installed during winding under tension to ensure duct height consistency and stable oil flow paths.
Conclusion: Why Oil Duct Spacers Matter
Though small in size, transformer oil duct spacers have a large impact on:
- Cooling system performance
- Electrical insulation reliability
- Long-term mechanical stability
They’re critical for efficient thermal management and safer operation—especially in high-power transformer applications.
Contact Us
Interested in oil duct spacers or insulation kits?
📩 Request technical drawings or material samples
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Phone: +86-15958243831
Email: jessie.feng@sidanm.com
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