126kV-550kV PTFE nozzle

The 126kV-550kV polytetrafluoroethylene (PTFE) nozzle is a key component of the arc extinguishing chamber of high-voltage circuit breakers (such as LW30-126, LW36-126, etc.), and its performance directly affects the breaking capacity and service life of the circuit breaker. The following is a comprehensive technical analysis:
1、 Core performance requirements
Electrical and Thermal Stability
126kV nozzle needs to withstand 550kV lightning impulse voltage, 252kV nozzle needs to meet 950kV impulse voltage, and surface electric field strength ≤ 15kV/mm
Long term working temperature needs to adapt to -200 ℃~260 ℃, and short-term high temperature resistance up to 300 ℃ (such as LW36-126 circuit breaker nozzle)
Mechanical and erosion resistance
It needs to withstand a 50kA short-circuit current impact, with a nozzle inner wall ablation depth of ≤ 0.1mm/time
By using imported PTFE with trace components such as graphite and carbon fiber, the erosion resistance is improved by more than 30%
2、 Materials and processes
Forming process
Adopting the molding sintering process, the sintering temperature is 360 ℃~380 ℃, the pressure is ≥ 10MPa, and the density is ensured to be ≥ 2.15g/cm ³
Surface enhanced bonding strength with metal flanges through plasma treatment or chemical etching
3、 Typical Applications and Standards
Application scenarios
126kV nozzle is used for urban substation circuit breakers (such as LW30-126/3150-40 models)
Industry standards
Must comply with GB/T 11022-2020 "Common Technical Requirements for High Voltage Switchgear and Control Equipment Standards"
The breaking performance test requires passing 100 full capacity short-circuit current tests (such as 40kA/3s)
4、 Technological Challenges and Development
Anti erosion optimization
Reduce arc erosion rate through gradient material design (such as PTFE outer layer+silicon carbide inner layer)

Note: Customization with drawings is available