U70BL, ANSI 52-3 Glass Insulator Disc Suspension Ball & Socket (LXP2-70) — 70kN Toughened Glass Insulator for 33–66kV Overhead Lines
The U70BL, ANSI 52-3 Glass Insulator Disc Suspension Ball & Socket (LXP2-70) is a ball-and-socket type disc suspension insulator with a rated mechanical failing load of 70kN (15,000 lbs).
Manufactured by TCI Insulators, this insulator is engineered for insulation and mechanical support of overhead transmission and distribution lines operating at 33kV to 66kV.
It combines high-strength toughened glass with hot-dip galvanized steel hardware, delivering reliable performance in urban power grids, rural distribution networks, railway electrification systems, and industrial supply lines.
The U70BL designation follows the IEC naming convention: U = disc suspension insulator, 70 = rated mechanical failing load of 70kN, B = ball-and-socket coupling type, L = long spacing (146mm).
The ANSI 52-3 classification corresponds to the ANSI C29.2 standard for wet-process porcelain and toughened glass insulators. The unit is fully compliant with IEC 60383-1, GB/T 1001.1, and ANSI C29.2, with connection structures conforming to GB/T 4056-2008 (IEC 60120) and BS 3288 Part III.
U70BL, ANSI 52-3 Glass Insulator Technical Specifications
Dimensions
| Parameter | Value |
| Diameter (D) | 10 inch (255mm) |
| Spacing (H) | 5 3/4 inch (146mm) |
| Leakage Distance | 12 5/8 inch (320mm) |
| Coupling Size | 16 |
The longer 146mm spacing provides additional mechanical clearance and allows for greater flexibility in string configurations, while the optimized aerodynamic umbrella profile with deep concentric ribs effectively prevents water-film formation, reducing flashover risk in heavy rain, fog, and moderate pollution environments.
U70BL, ANSI 52-3 Glass Insulator Mechanical Values
| Parameter | Value |
| Mechanical Failing Load | 15,000 lbs (70kN) |
| Tension Proof | 7,500 lbs (35kN) |
The 70kN mechanical failing load provides exceptional tensile strength to withstand conductor tension, wind loads, and ice loads. Each unit undergoes a routine proof test at 35kN to guarantee reliability.
U70BL, ANSI 52-3 Glass Insulator Electrical Values
| Parameter | Value |
| Low Frequency Dry Flashover Voltage | 80kV |
| Low Frequency Wet Flashover Voltage | 50kV |
| Critical Impulse Flashover Voltage, Positive | 125kV |
| Critical Impulse Flashover Voltage, Negative | 130kV |
| Low Frequency Puncture Voltage | 130kV |
The toughened glass dielectric delivers superior insulation capability, withstanding power frequency voltages and impulse surges while maintaining stable performance across varying climatic conditions.
Radio Influence Voltage (RIV) Data
| Parameter | Value |
| Test Voltage RMS to Ground | 10kV |
| Maximum RIV at 1000 kHz | 50μV |
Packing and Shipping Data
| Parameter | Value |
| Net Weight, Approximate | 3.8kg |
U70BL, ANSI 52-3 Glass Insulator Key Features
ANSI 52-3 Compatibility — Designed to meet ANSI C29.2 requirements, the LXP2-70 (U70BL) is interchangeable with ANSI 52-3 class insulators, ensuring seamless replacement and compatibility with North American transmission and distribution systems.
Longer Spacing (146mm) — The extended 146mm spacing offers greater mechanical clearance and allows for customized string lengths, making it suitable for applications where additional spacing is required without compromising electrical performance.
Automatic Zero-Value Self-Shattering — When an electrical or mechanical fault occurs, toughened glass self-shatters, leaving the mechanical string intact. Patrol teams can spot defects instantly from the ground without climbing towers or using expensive testing equipment.
Superior Anti-Aging & Weather Resistance — Unlike porcelain or composite materials, toughened glass resists chemical aging, UV radiation, and retains dielectric properties for decades of service.
High Mechanical Strength — The 70kN rated failing load ensures dependable performance under extreme mechanical stress, including heavy ice loading and high wind zones.
Flexible Locking Pin Options — The U70BL accommodates either W-pin or R-pin locking mechanisms; R-pin is used as the standard configuration unless otherwise specified.
Hot-Dip Galvanized Hardware — The cap and pin are made from hot-dip galvanized ductile iron and forged steel, assembled with high-strength aluminous cement. A stainless steel split pin secures the coupling of units. An optional zinc sleeve (sacrificial anode) is available for heavy-pollution lines.
U70BL, ANSI 52-3 Glass Insulator Applications
- 33kV–66kV overhead power transmission and distribution lines
- Railway electrification systems
- Industrial power grids and substations
- Urban and rural power network construction
- Tension strings and suspension strings
- ANSI-compatible transmission projects
Why Choose U70BL, ANSI 52-3 Glass Insulator TCI Insulators?
TCI Insulators is a trusted manufacturer of composite and porcelain insulators, serving global utilities and contractors since 2002. With state-of-the-art testing facilities and rigorous quality assurance processes, TCI conducts comprehensive product tests including ultraviolet aging, hardness, flame-retardant, tracking, and leakage current tests according to national and international standards.
Our disc suspension insulator system supports mechanical and electrical loads from 10,000 to 50,000 lbs, available across all voltage levels for both distribution and transmission systems, fully compliant with IEC and ANSI standards.
Related Products
- LXP-40 (U40B) Ball & Socket Disc Suspension Insulator — 40kN rated, for 10–35kV lines
- LXP1-70 (U70BS) Ball & Socket Disc Suspension Insulator — 70kN rated, standard spacing for 33–66kV lines
- LXP-100 (U100BL) Ball & Socket Disc Suspension Insulator — 100kN rated, for high-voltage transmission
- Porcelain Disc Suspension Insulators — U40B through U300B IEC class range
- Composite Hollow Insulators — For instrument transformers and circuit breakers
Internal Links:
- TCI Insulators Homepage
- Disc Suspension Insulators
- Toughened Glass Insulators
- Composite Hollow Insulators
- Contact TCI Insulators
External Links:
- IEC 60383-1 — Insulators for Overhead Lines
- GB/T 1001.1 — Insulators for Overhead Lines with a Nominal Voltage Above 1,000 V
- ANSI C29.2 — Wet-Process Porcelain and Toughened Glass Insulators
- IEC 60120 / GB/T 4056 — Ball and Socket Coupling Dimensions
- BS 3288 Part III — Insulator Connections
All specifications are subject to change without notice. For the most current technical data and pricing, please contact TCI Insulators directly at www.tcinsulators.com.


