Porcelain Insulators for Overhead Transmission Lines
Porcelain insulators for overhead transmission and distribution lines and substations, manufactured to GB, ANSI, BS, DIN, AS and IEC standard designs. Supports system voltages up to 500kV AC and 400kV DC. Designed for use in suspension, tension, and dead-end applications on overhead lines. Engineers available to develop non-standard designs for specific applications.
What Goes Wrong on These Projects
- Mismatched hardware on rebuild projects prevents direct replacement of insulators
- Polymer insulators degrade under UV exposure and cannot be visually inspected for internal damage
- Insufficient leakage distance leads to flashover in polluted or coastal environments
- Lack of mechanical strength in low-rated insulators forces string redesigns during line uprating
- Unclear application voltage ratings lead to incorrect insulator selection in procurement
What Buyers on These Projects Need
- Insulators that match existing tower hardware for direct replacement
- Mechanical strength that supports high tension loads without failure
- Electrical performance that meets or exceeds system voltage and pollution level requirements
- Long-term durability under UV, corona, and environmental stress
- Custom designs for non-standard mounting, voltage, or environmental conditions
Typical Scenarios
- Replacement of insulators on existing overhead transmission lines where hardware must remain compatible
- Construction of new transmission lines requiring insulators rated for 500kV AC or 400kV DC systems
- Reconstruction of lines in coastal or industrial areas where salt or dust increases pollution risk
- Installation of insulators in high-wind or ice-loaded zones requiring high mechanical strength
- Projects requiring non-standard insulator designs due to unique tower geometry or clearance constraints
Products for Overhead Transmission Lines
How an Enquiry Runs
Body preparation and forming of the porcelain shell using standard or custom dimensions
Glazing and high temperature firing to achieve required dielectric and mechanical properties
Cementing of metal fittings (clevis, tongue, cap, pin) to the porcelain body using Portland cement
Routine proof load testing at the specified load for each insulator type
Electrical testing including dry and wet flashover, impulse flashover, and radio influence voltage checks
Inspection for glaze defects, cement cracks, and mechanical damage before packing
Delivery and Support
- Insulators shipped in standard wooden pallets with protective packaging
- Packing designed to prevent movement and impact damage during transit
- Custom packaging available for non-standard or high-value orders
- Shipping to more than 40 countries including America, Canada, Australia, Brazil, Ecuador, Russia, Greece, Cyprus, India, Viet Nam, Sri Lanka, Pakistan, Tanzania, and Kenya
- Contact us for shipping details, customs documentation, and delivery timelines
Overhead Transmission Lines FAQ
What system voltages do your insulators support?
Our insulators are designed for overhead line and substation applications up to 500kV AC and 400kV DC system voltages.
Can you supply insulators with different coupling types?
Yes. We build to GB, ANSI, BS, DIN, AS and IEC standard designs. Provide the coupling class and we will confirm availability.
What is the maximum working load for the ANSI 52-4 clevis type insulator?
The maximum working load is 7,500 pounds (33.5kN). This is the load applied under normal operating conditions including wind and ice.
Do you perform proof testing on every unit?
Yes. Every unit is routine proof tested at the specified load. For example, the ANSI 52-4 is proof tested at 7,500 pounds (33.5kN).
What certifications do you hold?
Our manufacturing facilities are certified to ISO 9001:2008. We do not claim any other certification.
Can you make a non-standard insulator for my project?
Yes. We design insulators for specific non-standard applications. Our engineers are available to assist with development.
Which countries do you supply?
Customers in more than 40 countries use our insulators, including America, Canada, Australia, Brazil, Ecuador, Russia, Greece, Cyprus, India, Viet Nam, Sri Lanka, Pakistan, Tanzania, and Kenya.
Guides Worth Reading First
Choosing Between Pin Post and Suspension Insulators
How to select between pin type, line post, station post, suspension disc, strain or spool insulators based on mounting, mechanical loading a
Creepage Distance and Pollution Performance
Creepage distance values for IEC C4-125 (500mm), ANSI TR-208 (610mm), ANSI 57-2 (559mm), and ANSI 56-3 (533mm) insulators. How to compare po
Specifying Insulators for Overhead Transmission Lines
Send the schedule, the standard your tender uses and the destination. We will mark which lines map to classes we already produce.