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Shandong Jinhao Electrical Technology Co., Ltd. · Linyi Shandong China
Linemen installing toughened glass insulator strings on a high voltage transmission tower
Toughened Glass Insulators Since 2015

Insulator Strings That Stay On The Line For 30 To 50 Years

We manufacture cap and pin toughened glass insulators from 40 kN to 550 kN for utilities and EPC contractors building 10 kV to 800 kV AC and DC lines. Every unit is thermal shock screened before it ships, so failures show up in our furnace and not on your tower.

Ultra high voltage transmission towers crossing forested hills on the Longdong to Shandong DC line
Built For UHV Projects

Profiles Matched To The Pollution You Actually Have

Standard, anti-fog, aerodynamic, two-alternating and three-alternating profiles, with creepage from 190 mm to 550 mm. Tell us the site conditions and we will size the string instead of selling you a catalogue number.

Automated toughened glass insulator production line inside the Jinhao Electrical plant in Linyi Shandong
Our Own Factory In Linyi Shandong

One Plant From Glass Batch To Packed Pallet

A 30-acre base with automated glass shell forming, tempering and cementing lines plus chemical and electrical test laboratories. No trading house between you and the furnace.

2015 Established
30 acres Production Base
200+ Employees
10-800 kV Voltage Range
40-550 kN Mechanical Load
15-35 days Lead Time
What We Do

Insulators Chosen By Line Conditions Not By Catalogue Number

Four things decide whether a string survives its design life: voltage, mechanical load, deposit type and profile. We build all five profiles in-house so the answer is never limited by what we happen to stock.

What We Make

Cap and pin toughened glass disc suspension insulators and the precision power fittings that go with them, in standard, anti-fog, aerodynamic, two-alternating and three-alternating profiles.

Who We Serve

Transmission and distribution utilities, grid EPC contractors, substation builders, railway electrification projects and insulator distributors supplying those markets.

What Problem We Solve

Pollution flashover, hidden insulator defects that only appear after energisation, and long replacement outages. Toughened glass fails visibly and self-destructs, so a line patrol finds the bad unit instead of a fault recorder.

Why Customers Choose Us

We run the glass furnace, the tempering line and the cementing line ourselves, screen every shell with a thermal shock test, and hold ISO 9001, ISO 14001, ISO 45001 certification plus one national invention patent and four utility model patents.

Product Range

Five Profiles Across Five Pollution Environments

Standard, anti-fog, aerodynamic, two-alternating and three-alternating discs from 40 kN to 160 kN in our listed range, with ratings to 550 kN developed for project supply.

Every Model

Cap And Pin Toughened Glass Insulators

Each disc below is listed with its full mechanical, electrical and dimensional data taken from our test records.

U40B standard profile toughened glass insulator disc 175 mm diameter with 11 ball coupling
Standard Profile

U40B · 40 kN

A 40 kN standard profile disc with 110 mm spacing, 175 mm diameter and 190 mm creepage, weighing 1.8 kg. The lightest unit in our…

Creepage 190 mm Ø 175 mm Coupling 11
U70BS standard profile toughened glass insulator disc 255 mm diameter with 16 ball coupling
Standard Profile

U70BS · 70 kN

A 70 kN standard profile disc with 127 mm spacing, 255 mm diameter and 320 mm creepage, weighing 3.6 kg. The volume workhorse for…

Creepage 320 mm Ø 255 mm Coupling 16
U70BLP anti-fog profile toughened glass insulator with deep ribs and 280 mm diameter
Anti-Fog Profile

U70BLP · 70 kN

A 70 kN anti-fog disc with 146 mm spacing, 280 mm diameter and 450 mm creepage, weighing 5.3 kg. Deep under-ribs hold a dry band…

Creepage 450 mm Ø 280 mm Coupling 16
U160BD aerodynamic profile toughened glass insulator with wide 420 mm open shed
Aerodynamic Profile

U160BD · 160 kN

A 160 kN aerodynamic disc with 155 mm spacing, 420 mm diameter and 380 mm creepage, weighing 8.5 kg. The widest disc in our range…

Creepage 380 mm Ø 420 mm Coupling 20
U160BSV two-alternating profile toughened glass insulator with alternating shed diameters
Two-alternating Profile

U160BSV · 160 kN

A 160 kN two-alternating disc with 155 mm spacing, 300 mm diameter and 450 mm creepage, weighing 8.4 kg. Alternating shed diameters…

Creepage 450 mm Ø 300 mm Coupling 20
U160BLT three-alternating profile toughened glass insulator with three stepped shed diameters
Three-alternating Profile

U160BLT · 160 kN

A 160 kN three-alternating disc with 155 mm spacing, 330 mm diameter and 550 mm creepage, weighing 8.9 kg. The longest creepage…

Creepage 550 mm Ø 330 mm Coupling 20

See The Full Product Table

The Selection Problem

Pollution Class Alone Does Not Choose A Profile

Two sites at the same IEC class can need opposite geometry. Deep ribs hold a dry band in salt fog and trap dust in a desert. Start from what is landing on the shed.

Clean And Mild Pollution

  • Light atmospheric contamination and low dust concentration
  • Minimal industrial saline or chemical deposits
  • Rural suburban and non-industrial regions
  • Moderate climate with stable humidity and no extreme sand or dust
Matching Profile

Heavy Industrial Pollution

  • High levels of chemical fumes industrial emissions and conductive pollutants
  • Frequent formation of conductive or corrosive surface deposits
  • Industrial zones chemical plants power plants and high-density urban areas
  • Severe electrical insulation stress from pollution layers
Matching Profile

Desert And Sand-Dust Areas

  • Arid climate strong winds and frequent sand and dust storms
  • Large temperature variations and intense ultraviolet radiation
  • Dominated by dry abrasive sand and mineral dust
  • Low conductivity but high mechanical abrasion and accumulation risk
Matching Profile

Heavy Solid Particle Pollution

  • Extreme concentration of coal dust cement dust ore powder and metal particles
  • Dry dense and strongly adherent solid deposits
  • Mining areas cement plants steel mills and coal-fired industrial zones
  • Combined high pollution accumulation and potential conductive layer formation
Matching Profile
Who We Serve

Where Our Insulators Go To Work

From 10 kV distribution feeders to ±800 kV UHVDC corridors, plus substation yards and railway electrification.

High voltage substation switchyard with busbar structures and insulator strings

Substations And Switchyards

Substation yards concentrate equipment, heat and pollution in a small footprint. Strings here are short, heavily loaded and surrounded by structures…

Inside The Plant

From Quartz Sand To A Screened Disc

Nine controlled stages on a 30-acre base in Linyi. The first four are below and the full sequence continues on our company page.

Bagged quartz sand and batch materials staged in the Jinhao raw material warehouse
1

Raw Material Preparation And Batching

High-purity quartz sand, feldspar, limestone, dolomite, soda ash and potassium carbonate are tested for chemical composition, particle size and moisture on arrival. Only qualified lots are released. Quartz sand is dried to avoid moisture-induced defects, then weighed and blended in a forced vertical-axis mixer to a fixed ratio.

Continuous glass melting furnace producing homogeneous glass melt for insulator shells
2

Melting And Refining At 1500 To 1600 Degrees C

The batch is fed into a continuous glass furnace. Raw materials react to form silicates, the silicates melt into a glassy state, fining agents clear the bubbles that would otherwise become internal defects, stirring homogenises the composition, and the melt is cooled to a moulding viscosity of around 1000 degrees C.

Rotating press forming a toughened glass insulator shell from a molten glass gob
3

Press Molding

A molten gob is dropped into a precision mould on a rotating press at around 1000 degrees C. A stamp forms the internal cavity while the mould defines the disc profile. Glass volume and pressing pressure are controlled to hold uniform wall thickness, which is what keeps breakage low during toughening.

Freshly pressed glass insulator shells passing through the homogenization furnace
4

Homogenization Soaking

Freshly pressed shells pass through a homogenization furnace held at uniform high temperature. This removes residual stress left by moulding and puts every shell into the same thermal state before toughening, so the quench acts evenly.

See All Nine Production Stages

Quality And Compliance

Certified Systems Behind Every Batch

Testing is carried out to IEC 60383 and GB/T 1001.1, with routine electrical and mechanical checks on 100 percent of finished units before delivery.

  • ISO 9001 Quality Management System
  • ISO 14001 Environmental Management System
  • ISO 45001 Occupational Health and Safety Management System
  • ISO 20001:2018 Energy Management System
  • SR10:2015 / ISO 26000-2011 Social Responsibility Management System
  • CMA and CNAS recognition on selected products
  • National High-tech Enterprise
  • Science and Technology Small & Medium-sized Enterprise
Second thermal shock test station verifying toughened glass insulator stability
The second thermal shock test verifies structural stability and thermal shock resistance under repeated temperature change, screening out units with insufficient tempering stress or internal microcracks.
Project Record

Lines We Have Supplied

Including a 420 kN disc developed for the 750 kV Kuqa to Aral and Bachu project and a 550 kN disc for the ±800 kV Longdong to Shandong project.

Customer Feedback

What Utility Buyers Tell Us

Feedback carried over from our previous site, attributed as originally published.

“Working with your company has been a reliable and efficient experience. Your glass insulators meet strict international standards and perform consistently well in our power transmission projects. We highly appreciate your professional service and on-time delivery.”

CEB

“We have cooperated for many years, and your team always provides excellent technical support and customized solutions. The quality and stability of your glass insulators have helped us improve project safety and reduce maintenance costs.”

NTDC

“We have been importing their glass insulators for over three years for projects in Southeast Asia. What impresses us most is their quality consistency and the reliability of their supply chain. Despite peak season demands, they always meet our tight delivery schedules.”

EDC

“We required a special design of glass insulators to withstand high pollution levels in coastal areas. Their R&D team worked closely with us to develop a customized anti-fouling solution, and their rapid prototyping ability took the product from concept to approval quickly.”

EGAT
Knowledge Center

Engineering Guides For Insulator Buyers

Selection, comparison and failure-mode guides written for procurement and line engineers.

Answers

Questions Buyers Ask First

Are you a manufacturer or a trading company?

We are a manufacturer of toughened glass insulators with our own factory, R&D team and production lines in Bancheng Town, Lanshan District, Linyi City, Shandong Province, established on 22 July 2015.

What voltage levels do your glass insulators cover?

Our product specifications cover 10 kV to 800 kV, for AC, DC and all lower voltage systems used on transmission lines and in power stations.

What mechanical failing loads are available?

Common ratings include 40 kN, 70 kN, 100 kN, 120 kN, 160 kN, 210 kN, 240 kN, 300 kN, 420 kN and 550 kN. Custom loads are available for special projects.

What is your production lead time?

Normally 15 to 35 days after order confirmation and deposit, depending on quantity and production schedule.

Can I get samples for testing before a bulk order?

Yes. We provide sample support for pre-delivery testing and verification, and we accept both small trial orders and large bulk orders.

Which standards do your insulators comply with?

All our glass insulators comply with IEC 60383 and GB/T standards under an ISO 9001 quality management system. Some models also hold ANSI, BS, AS or DIN certification.

Send Us Your Line Conditions

Voltage level, mechanical load, pollution environment and quantity. With those four we quote a specific model with its test data instead of sending a catalogue.