1. Basic structure and materials
Material: Tempered glass is used as the main insulation body, with smooth surface, good aging resistance and weather resistance.
Structure:
Umbrella skirt design: Multi layer umbrella disc structure (possibly bell shaped or deep edged), increases creepage distance, and prevents pollution flashover.
Metal accessories: Top iron cap and bottom steel feet, usually hot-dip galvanized cast steel, providing mechanical connections and load-bearing capacity.
Adhesive: High strength cement or adhesive used to fix glass components and metal accessories.
2. Analysis of Model Meaning
U: May represent "suspension type" (suspension type insulator) or according to the manufacturer's definition.
70: Usually represents the rated mechanical failure load (such as 70kN, about 7 tons).
B: May refer to connection methods (such as ball and socket connections) or structural improvement models.
3. Key performance parameters
Mechanical strength: The rated mechanical load is 70kN, and the safety factor is usually ≥ 2.5 (actual failure load ≥ 175kN).
Electrical performance:
Power frequency wet withstand voltage: ≥ 45kV (specific value to refer to manufacturer's data).
Lightning impulse withstand voltage: ≥ 120kV.
Creepage distance: approximately 400-450mm (may vary depending on design).
Structural height: approximately 140-160mm, disc diameter approximately 255-280mm (slightly different manufacturers).
4. Core advantages
Zero value self explosion: Defects in tempered glass can cause insulators to self explode, making it easier for maintenance personnel to quickly identify faults.
Strong corrosion resistance: suitable for harsh environments such as industrial pollution and coastal high salt spray.
Long lifespan: Inorganic materials are not prone to aging and can have a lifespan of over 30 years.
Maintenance free: No need to periodically detect zero values, reducing operation and maintenance costs.
5. Application scenarios
Voltage level: 35kV~220kV transmission line (to be adjusted according to the number of series connections).
Applicable environment: It is mostly used in areas with pollution levels of III and above (such as industrial areas and coastal areas).
Typical use: Suspension string for straight tower, tension string, or insulation support for jumper wires.
6. Compliance with standards
Chinese standard: GB/T 1001.1 (disc-shaped suspension insulators).
International standards: IEC 60383, ANSI C29.2, etc. (specific to manufacturer certification).
7. Precautions
Installation: Special tools are required to avoid uneven stress on metal accessories.
Transportation: To prevent glass damage caused by collisions.
Pollution management: In heavily polluted areas, regular cleaning or the use of anti fouling flash coatings should be combined.
8. Comparison with other insulators
Characteristic glass insulator U70B ceramic insulator composite insulator
Self checking ability: Zero value self explosion requires regular testing and infrared detection
Good resistance to pollution and flash, generally excellent
Heavy and light in weight
High impact resistance and high fragility
summarize
U70B glass insulator is a reliable and economical choice for high-voltage transmission lines, especially suitable for areas that require long-term stable operation and difficult maintenance.
| Type |
|
Ball and socket type |
Tongue-ball |
| IEC-standard |
|
U70BS |
U70BL |
|
U70C |
| Factory-standard |
|
|
|
PS70I |
|
| Standard coupling, d |
mm |
16A |
16A |
16A |
16C |
| Mechanical failing load |
kN |
70 |
70 |
70 |
70 |
| Mechanical routine test |
kN |
56 |
56 |
56 |
56 |
| Diameter of the insulating part, D |
mm |
255 |
255 |
255 |
255 |
| Nominal Spacing, H |
mm |
127 |
146 |
146 |
146 |
| Nominal creepage distance |
mm |
320 |
320 |
407 |
320 |
| Power frequency puncture voltage |
kV |
130 |
130 |
130 |
130 |
| power frequency withstand voltage - dry |
kV |
70 |
70 |
72 |
70 |
| power frequency withstand voltage - wet |
kV |
40 |
40 |
42 |
40 |
| Impulse puncture voltage |
P.U |
2.8 |
2.8 |
2.8 |
2.8 |
| Radio influence voltage 10kV 1MHz |
μv |
50 |
50 |
50 |
50 |
| Corona visual test |
kV |
18/22 |
18/22 |
18/22 |
18/22 |
| Power frequency electric arc voltage |
ka |
0.12s/20kA |
0.12s/20kA |
0.12s/20kA |
0.12s/20kA |
| Weight |
kg |
3.5 |
3.6 |
4.3 |
3.8 |
production line
Audited Supplier 
){kind=link}