Fiberglass Insulation Tubes Used in Surge Arresters | Selection Guide

Time: 01-07 2026 Auther: Xujue Electrical

I. Core Selection Principle The selection of fiberglass insulation tubes for surge arresters should be based on the ...

I. Core Selection Principle

The selection of fiberglass insulation tubes for surge arresters should be based on the system voltage level, while comprehensively considering mechanical strength, structural dimensions, service environment, and applicable standards. Continuous filament-wound FRP tubes with low water absorption and high dielectric performance are strongly recommended.

Epoxy Fiberglass Winding Tube

II. Key Selection Parameters (Must Be Confirmed)

System Voltage Level (Primary Criterion)

System Voltage	Typical Application
≤10 kV	Distribution surge arresters
35 kV	Substations
66 / 110 kV	Transmission systems
220 kV	High-voltage power grids
500 kV	Extra-high voltage systems

Higher voltage levels require longer tubes, thicker walls, and greater insulation margins.

Mechanical Strength Class (Critical)

Key parameters to be verified:
Axial compressive strength
Bending strength
Tensile strength

Application Scenario	Recommended Strength Class
Conventional substations	Standard strength
Transmission line arresters	High strength
High wind / seismic areas	Reinforced type

Line surge arresters require high mechanical strength fiberglass tubes.

Structural Dimension Selection

Key dimensions:

Outer Diameter (OD)
Inner Diameter (ID)
Wall Thickness
Effective Length

Selection principles:

ID ≥ ZnO varistor column diameter + assembly allowance
Wall thickness increases with voltage level and mechanical load
Ensure sufficient strength for end fittings and hardware installation

Electrical Performance Requirements

Typical recommended values:

Volume resistivity: ≥10¹² Ω·cm
Power-frequency withstand voltage: compliant with voltage class
Partial discharge: ≤10 pC
Low dielectric loss and long-term stability

Environmental Condition Selection

Service Environment	Recommended Configuration
High humidity / heavy rain	Low water absorption FRP
Coastal salt fog	Corrosion-resistant resin system
Industrial pollution	High-density filament-wound tube
Cold regions	Low-temperature crack-resistant formulation
High-temperature regions	High Tg epoxy resin system

Materials and Manufacturing Process (Key Point)

Recommended

Continuous fiberglass filament winding process
E-glass or ECR-glass fibers
High-purity epoxy resin systems

Not Recommended

Chopped fiber tubes
Conventional extruded insulation tubes
Recycled resin materials

III. Typical Selection Examples (Reference)

Project	Selection Approach
110 kV substation surge arrester	Standard-strength FRP tube with conventional wall thickness
110 kV transmission line arrester	Reinforced tube with high bending strength
220 kV coastal project	Salt-fog-resistant, low water absorption resin system
500 kV EHV system	Thick-walled filament-wound tube with high safety margin

IV. Quick Selection Checklist (For Engineering / Procurement)

System voltage level
Mechanical load requirements
Inner / outer diameter and length
Service environment
Material and manufacturing process
Applicable standards

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