Insulators: Three Major Materials, Specialized Manufacturers Dominate
The Chinese insulator market is divided into three main categories based on material: porcelain insulators, glass insulators, and composite insulators (silicone rubber). Manufacturers are mainly specialized manufacturers and state-owned enterprises: Xi’an Porcelain & Electric Co., Ltd. (XPE) leads the market share in ultra-high voltage (UHV) insulators (according to public information, its UHV project winning bid share exceeds 50%), Dalian Porcelain & Electric Co., Ltd. is the main manufacturer of glass insulators, and there are numerous composite insulator manufacturers. Industry insiders point out that when choosing “what are the insulator manufacturers and suppliers,” one should select based on material and voltage level—for UHV, choose state-owned enterprises with proven track records;
for line insulators, choose specialized manufacturers; and for distribution and low-voltage, choose brand-name manufacturers.
Main Manufacturer Distribution
- XD Porcelain Insulators (China XD Group): Mainstay of porcelain insulators and UHV insulators, with extensive UHV operation experience and the strongest qualifications;
- Dalian Porcelain Insulators: Leading professional in glass insulators, with large exports of glass insulators for power lines;
- Composite Insulator Manufacturers: Changgao Group, Jinlihua Electric, Chint, etc., with mature silicone rubber composite insulator product lines and wide applications in power distribution and lines;
- Regional Specialized Manufacturers: Insulator manufacturers with testing qualifications in various regions, serving local power grids and industrial projects;
- Supporting Manufacturers: Numerous supporting manufacturers for insulator hardware and accessories, allowing for comprehensive procurement.
Five Key Factors in Choosing a Manufacturer
First, material selection.
Porcelain insulators (pollution resistance, mechanical strength), glass insulators (self-explosion detection, zero-value self-breakage), and composite insulators (lightweight, pollution-resistant, maintenance-free) should be selected according to the application scenario.
Secondly, electromechanical performance is crucial. Mechanical load (rated and breaking load), insulation distance, and creepage distance (pollution level matching) must meet the line requirements, based on type test reports.
Thirdly, type testing is required.
A type test report from a national testing institution (GB/T 1001 series, GB/T 19519 composite insulators, etc.) is necessary, specifying the corresponding model. Fourthly, operational performance is essential.
Insulators for UHV and high-voltage levels must have operational performance records to support their specifications.
Fifthly, matching and delivery are important.
Complete insulator and fitting sets are provided to reduce installation problems; delivery dates and packaging (to prevent transportation damage) should be confirmed.
Selection by Scenario
UHV and Extra-High Voltage: Manufacturers with UHV performance such as Xi’an Electric Porcelain and Xi’an Porcelain; Transmission Lines: Specialized line manufacturers such as Dalian Porcelain (Glass) and Changgao (Composite); Distribution and Indoor: Brand manufacturers such as Chint; Polluted and Coastal Environments: Prioritize composite insulators or high creepage distance porcelain insulators;
Export Projects: Confirm IEC standards and destination country line requirements.
Pitfall Avoidance Tips
First, “Inflated Mechanical Strength Labels.”
Insufficient destructive load can lead to string breakage accidents; verify test reports during acceptance.
Second, “Inferior Materials.”
Substandard silicone rubber formulations in composite insulators cause rapid aging and cracking; inspect the factory to check the formulation and aging tests.
Third, “Transportation Damage.”
Brittle cracking of insulator porcelain components is common; confirm packaging and acceptance upon arrival.
Fourth, “Inconsistent Reports.”
Type test reports must correspond to the purchased model.
Trends and Reminders
Insulators are moving towards “composite + pollution-resistant”: Composite insulators are rapidly replacing porcelain insulators in power distribution networks, and high-pollution-flashover-resistant insulators are becoming increasingly common in coastal and industrial pollution areas.
For purchasers, it is recommended to “select manufacturers based on material and voltage, dual-core electromechanical performance and testing, and lock in complete sets,” and to include mechanical load and creepage distance in the contract.
Insulators are the “safety buffer” for power transmission;
choosing the right manufacturer ensures reliable line insulation.
