Established in December 2002 with a registered capital of 508 million Yuan, Jiangxi QOCI Electric Co. Ltd has emerged as a premier force in high-voltage insulation manufacturing. Located in the Luxi County Industrial Park of Pingxiang, Jiangxi Province—the historical heartland of China's porcelain and industrial insulation sector—our state-of-the-art facility spans over 70,000 square meters.
Driven by industrial automation and deep material science research, QOCI Electric maintains an annual production capacity of 39,000 tons of toughened glass insulators. With 53+ senior engineering technicians and 26+ national patents, we supply standard, anti-pollution, aerodynamic, double-shed, and silicone-coated (RTV) toughened glass insulators for grids worldwide.
The Isolateur Ctv 175 U40b represents a specialized benchmark in toughened glass suspension insulation technology. Specifically engineered to meet stringently calculated mechanical and dielectric requirements, this insulator model incorporates a 40kN electromechanical failing load rating (U40b) combined with a geometry characterized by a 175mm structural spacing or optimized creepage profile (Ctv 175). It is widely deployed across transmission and distribution grids in French-influenced infrastructure markets, parts of Europe, and Africa, where grid reliability demands are extreme.
Our Isolateur Ctv 175 U40b is constructed via a thermal tempering process that creates deep internal compressive stresses. This toughened glass body is paired with a hot-dip galvanized steel cap, a high-tensile forged steel pin, and high-grade alumina cement. Below is an engineering overview of standard configurations for this category:
| Technical Parameter | Specification Limit / Standard Value |
|---|---|
| Nominal Mechanical Failing Load | 40 kN (U40B Standard Class) |
| Spacing (Height) | 175 mm / 146 mm Custom Profiles available |
| Shell Diameter | 175 mm (Standard Variant) / 255 mm (Extended Variant) |
| Power Frequency Withstand Voltage (Wet) | 40 kV to 45 kV |
| Lightning Impulse Withstand Voltage (Positive) | 75 kV to 80 kV |
| Standard Conformity | IEC 60305, IEC 60383, ANSI C29.2 |
The international power distribution landscape is undergoing a massive transformation, driven by integration of renewable energy sources, grid modernization, and increased frequency of extreme weather events. Key structural shifts shaping the manufacturing and sourcing of Isolateur Ctv 175 U40b units include:
The characteristic of the standard profile is that the leakage distance is higher than the value indicated for standard insulators in IEC 60305. The insulation part is designed with shallow and well spaced small ribs, which can be effectively self-cleaned by wind or rain.
The fog type profile is characterized by long and widely-spaced under-ribs so as to avoid arc bridging between adjacent ribs. It features a leakage distance/spacing ratio of around 3.2 and is particularly effective in coastal areas (Salt fog) as well as in polluted areas.
Design of insulating part with open profile is marked by absence of under-ribs and extended diameter of disk, with no under-ribs so as to avoid the accumulation of solid pollution deposits (dust, sand)on its lower surface. Open profile reduces pollutant accumulation on the surface.
The design of the insulation part has two external ribs. The elimination of the under-ribs reduces pollution build-up, and the surface of the insulator can self clean by strong winds. And facilitate manual cleaning when necessary. This profile provides equivalent leakage distance.
Triple-shed Type glass insulator is a key component in transmission lines, characterized by three layers of umbrella discs separated from each other on the insulation body. Thanks to this open shed design, they achieve self-cleaning during wind and rain and provide a longer creepage distance.
By connecting internal or external metal accessories (such as steel feet and flanges) to the grounding wire, reliable grounding can be achieved. The grounding function effectively guides lightning current, reduces line lightning damage, and protects the safety of lines and equipment.
Silicone-coated insulators offer an excellent alternative which guarantees optimum performance for high voltage overhead lines in areas with heavy pollution. They minimise leaking currents and thereby reduce operation and maintenance costs. The product used to coat the insulators is Room Temperature Vulcanization (RTV) silicone which contains mineral fillers embedded in the silicone itself. This silicone increases the hydrophobic nature of the insulator's surface, thereby improving its performance in polluted areas. Furthermore, the fillers absorb the energy of any possible electric arcs and serve to protect the integrity of the coating. Silicone-coated insulators are an economical solution because they eliminate the need to regularly clean glass insulators whilst still maintaining the mechanical reliability that glass suspension insulators have demonstrated over the years.
For power utilities, EPC (Engineering, Procurement, and Construction) contractors, and industrial developers, sourcing reliable insulating materials represents a primary pillar of infrastructure lifetime integrity. When bidding for national grid tenders or specifying components like the Isolateur Ctv 175 U40b, procurement teams must evaluate several critical parameters to ensure grid stability and project profitability:
High-quality manufacturers utilize exact chemical balances. The glass body must consist of high-purity silica sand, soda ash, and dolomite, processed through computer-controlled glass furnaces. Impurities such as ferrous compounds must be strictly minimized to guarantee a low thermal absorption rate and prevent spontaneous micro-shatters under intense direct sunlight. The iron cap and pin components should be forged with high-density metal structures and hot-dip galvanized according to ASTM A153 or ISO 1461 specifications to resist atmospheric corrosion in coastal and high-industrial zones.
A reputable factory must have testing labs capable of running Routine Tests (visual, mechanical, and electrical tests on 100% of finished pieces), Sample Tests (verification of dimensions, thermal shock, mechanical failing load, and galvanization thickness), and Type Tests. In particular, the thermal shock test requires insulators to withstand sudden temperature differentials of up to 100°C without mechanical failure or structural degradation.
Transmission line installation schedules are capital-intensive. Delayed supply chains can incur significant financial penalties. The factory's capacity (such as QOCI's 39,000 tons annual output) ensures stable volume commitments. Packaging must involve heavy-duty, seaworthy wooden crates or reinforced plastic pallets wrapped with UV-resistant film, preventing damage during transport across rugged terrain to installation zones.
Because grid requirements differ by state and country, working with a manufacturer that provides local engineering support is invaluable. The manufacturer must supply clear certificates of compliance with local utility standards (e.g., EDF specifications in France, ESKOM in South Africa, CELEC in Ecuador). The engineering team must be capable of custom-designing fitting configurations (ball-and-socket vs. clevis-tongue types) to match preexisting tower footprints.
As the global energy transition accelerates, the importance of electricity, renewable energy, and energy storage technologies is becoming increasingly critical. QOCI will showcase the new pre-coated RTV line.
Having withstood extreme environmental conditions including icing, high altitude, pollution, earthquakes and typhoons, China's insulator industry leads in UHV glass development.
On behalf of our team at Jiangxi QOCI Electric Co., Ltd, we encourage you to join us at IEEE PES T&D Conference & Exposition 2026, the powerhouse global event for electrical engineering.
Pingxiang, China, December 30, 2025- QOCI Electric, a leading global supplier of power equipment and solutions, officially confirmed today that they will lead a technical panel in Iraq.
